chrome/browser/themes/browser_theme_pack.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/themes/browser_theme_pack.h"
   6
   7 #include <limits>
   8
   9 #include "base/files/file.h"
  10 #include "base/memory/ref_counted_memory.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/stl_util.h"
  13 #include "base/strings/string_number_conversions.h"
  14 #include "base/strings/string_util.h"
  15 #include "base/strings/utf_string_conversions.h"
  16 #include "base/threading/sequenced_worker_pool.h"
  17 #include "base/threading/thread_restrictions.h"
  18 #include "base/values.h"
  19 #include "chrome/browser/themes/theme_properties.h"
  20 #include "chrome/common/extensions/manifest_handlers/theme_handler.h"
  21 #include "components/crx_file/id_util.h"
  22 #include "content/public/browser/browser_thread.h"
  23 #include "grit/theme_resources.h"
  24 #include "third_party/skia/include/core/SkCanvas.h"
  25 #include "ui/base/resource/data_pack.h"
  26 #include "ui/base/resource/resource_bundle.h"
  27 #include "ui/gfx/canvas.h"
  28 #include "ui/gfx/codec/png_codec.h"
  29 #include "ui/gfx/geometry/size_conversions.h"
  30 #include "ui/gfx/image/canvas_image_source.h"
  31 #include "ui/gfx/image/image.h"
  32 #include "ui/gfx/image/image_skia.h"
  33 #include "ui/gfx/image/image_skia_operations.h"
  34 #include "ui/gfx/screen.h"
  35 #include "ui/gfx/skia_util.h"
  36 #include "ui/resources/grit/ui_resources.h"
  37
  38 using content::BrowserThread;
  39 using extensions::Extension;
  40
  41 namespace {
  42
  43 // Version number of the current theme pack. We just throw out and rebuild
  44 // theme packs that aren't int-equal to this. Increment this number if you
  45 // change default theme assets.
  46 const int kThemePackVersion = 35;
  47
  48 // IDs that are in the DataPack won't clash with the positive integer
  49 // uint16. kHeaderID should always have the maximum value because we want the
  50 // "header" to be written last. That way we can detect whether the pack was
  51 // successfully written and ignore and regenerate if it was only partially
  52 // written (i.e. chrome crashed on a different thread while writing the pack).
  53 const int kMaxID = 0x0000FFFF;  // Max unsigned 16-bit int.
  54 const int kHeaderID = kMaxID - 1;
  55 const int kTintsID = kMaxID - 2;
  56 const int kColorsID = kMaxID - 3;
  57 const int kDisplayPropertiesID = kMaxID - 4;
  58 const int kSourceImagesID = kMaxID - 5;
  59 const int kScaleFactorsID = kMaxID - 6;
  60
  61 // The sum of kFrameBorderThickness and kNonClientRestoredExtraThickness from
  62 // OpaqueBrowserFrameView.
  63 const int kRestoredTabVerticalOffset = 15;
  64
  65 // Persistent constants for the main images that we need. These have the same
  66 // names as their IDR_* counterparts but these values will always stay the
  67 // same.
  68 const int PRS_THEME_FRAME = 1;
  69 const int PRS_THEME_FRAME_INACTIVE = 2;
  70 const int PRS_THEME_FRAME_INCOGNITO = 3;
  71 const int PRS_THEME_FRAME_INCOGNITO_INACTIVE = 4;
  72 const int PRS_THEME_TOOLBAR = 5;
  73 const int PRS_THEME_TAB_BACKGROUND = 6;
  74 const int PRS_THEME_TAB_BACKGROUND_INCOGNITO = 7;
  75 const int PRS_THEME_TAB_BACKGROUND_V = 8;
  76 const int PRS_THEME_NTP_BACKGROUND = 9;
  77 const int PRS_THEME_FRAME_OVERLAY = 10;
  78 const int PRS_THEME_FRAME_OVERLAY_INACTIVE = 11;
  79 const int PRS_THEME_BUTTON_BACKGROUND = 12;
  80 const int PRS_THEME_NTP_ATTRIBUTION = 13;
  81 const int PRS_THEME_WINDOW_CONTROL_BACKGROUND = 14;
  82
  83 struct PersistingImagesTable {
  84   // A non-changing integer ID meant to be saved in theme packs. This ID must
  85   // not change between versions of chrome.
  86   int persistent_id;
  87
  88   // The IDR that depends on the whims of GRIT and therefore changes whenever
  89   // someone adds a new resource.
  90   int idr_id;
  91
  92   // String to check for when parsing theme manifests or NULL if this isn't
  93   // supposed to be changeable by the user.
  94   const char* const key;
  95 };
  96
  97 // IDR_* resource names change whenever new resources are added; use persistent
  98 // IDs when storing to a cached pack.
  99 //
 100 // TODO(erg): The cocoa port is the last user of the IDR_*_[HP] variants. These
 101 // should be removed once the cocoa port no longer uses them.
 102 PersistingImagesTable kPersistingImages[] = {
 103   { PRS_THEME_FRAME, IDR_THEME_FRAME,
 104     "theme_frame" },
 105   { PRS_THEME_FRAME_INACTIVE, IDR_THEME_FRAME_INACTIVE,
 106     "theme_frame_inactive" },
 107   { PRS_THEME_FRAME_INCOGNITO, IDR_THEME_FRAME_INCOGNITO,
 108     "theme_frame_incognito" },
 109   { PRS_THEME_FRAME_INCOGNITO_INACTIVE, IDR_THEME_FRAME_INCOGNITO_INACTIVE,
 110     "theme_frame_incognito_inactive" },
 111   { PRS_THEME_TOOLBAR, IDR_THEME_TOOLBAR,
 112     "theme_toolbar" },
 113   { PRS_THEME_TAB_BACKGROUND, IDR_THEME_TAB_BACKGROUND,
 114     "theme_tab_background" },
 115 #if !defined(OS_MACOSX)
 116   { PRS_THEME_TAB_BACKGROUND_INCOGNITO, IDR_THEME_TAB_BACKGROUND_INCOGNITO,
 117     "theme_tab_background_incognito" },
 118 #endif
 119   { PRS_THEME_TAB_BACKGROUND_V, IDR_THEME_TAB_BACKGROUND_V,
 120     "theme_tab_background_v"},
 121   { PRS_THEME_NTP_BACKGROUND, IDR_THEME_NTP_BACKGROUND,
 122     "theme_ntp_background" },
 123   { PRS_THEME_FRAME_OVERLAY, IDR_THEME_FRAME_OVERLAY,
 124     "theme_frame_overlay" },
 125   { PRS_THEME_FRAME_OVERLAY_INACTIVE, IDR_THEME_FRAME_OVERLAY_INACTIVE,
 126     "theme_frame_overlay_inactive" },
 127   { PRS_THEME_BUTTON_BACKGROUND, IDR_THEME_BUTTON_BACKGROUND,
 128     "theme_button_background" },
 129   { PRS_THEME_NTP_ATTRIBUTION, IDR_THEME_NTP_ATTRIBUTION,
 130     "theme_ntp_attribution" },
 131   { PRS_THEME_WINDOW_CONTROL_BACKGROUND, IDR_THEME_WINDOW_CONTROL_BACKGROUND,
 132     "theme_window_control_background"},
 133
 134   // The rest of these entries have no key because they can't be overridden
 135   // from the json manifest.
 136   { 15, IDR_BACK, NULL },
 137   { 16, IDR_BACK_D, NULL },
 138   { 17, IDR_BACK_H, NULL },
 139   { 18, IDR_BACK_P, NULL },
 140   { 19, IDR_FORWARD, NULL },
 141   { 20, IDR_FORWARD_D, NULL },
 142   { 21, IDR_FORWARD_H, NULL },
 143   { 22, IDR_FORWARD_P, NULL },
 144   { 23, IDR_HOME, NULL },
 145   { 24, IDR_HOME_H, NULL },
 146   { 25, IDR_HOME_P, NULL },
 147   { 26, IDR_RELOAD, NULL },
 148   { 27, IDR_RELOAD_H, NULL },
 149   { 28, IDR_RELOAD_P, NULL },
 150   { 29, IDR_STOP, NULL },
 151   { 30, IDR_STOP_D, NULL },
 152   { 31, IDR_STOP_H, NULL },
 153   { 32, IDR_STOP_P, NULL },
 154   { 33, IDR_BROWSER_ACTIONS_OVERFLOW, NULL },
 155   { 34, IDR_BROWSER_ACTIONS_OVERFLOW_H, NULL },
 156   { 35, IDR_BROWSER_ACTIONS_OVERFLOW_P, NULL },
 157   { 36, IDR_TOOLS, NULL },
 158   { 37, IDR_TOOLS_H, NULL },
 159   { 38, IDR_TOOLS_P, NULL },
 160   { 39, IDR_MENU_DROPARROW, NULL },
 161   { 40, IDR_THROBBER, NULL },
 162   { 41, IDR_THROBBER_WAITING, NULL },
 163   { 42, IDR_THROBBER_LIGHT, NULL },
 164   { 43, IDR_TOOLBAR_BEZEL_HOVER, NULL },
 165   { 44, IDR_TOOLBAR_BEZEL_PRESSED, NULL },
 166   { 45, IDR_TOOLS_BAR, NULL },
 167 };
 168 const size_t kPersistingImagesLength = arraysize(kPersistingImages);
 169
 170 #if defined(USE_ASH) && !defined(OS_CHROMEOS)
 171 // Persistent theme ids for Windows.
 172 const int PRS_THEME_FRAME_DESKTOP = 100;
 173 const int PRS_THEME_FRAME_INACTIVE_DESKTOP = 101;
 174 const int PRS_THEME_FRAME_INCOGNITO_DESKTOP = 102;
 175 const int PRS_THEME_FRAME_INCOGNITO_INACTIVE_DESKTOP = 103;
 176 const int PRS_THEME_TOOLBAR_DESKTOP = 104;
 177 const int PRS_THEME_TAB_BACKGROUND_DESKTOP = 105;
 178 const int PRS_THEME_TAB_BACKGROUND_INCOGNITO_DESKTOP = 106;
 179
 180 // Persistent theme to resource id mapping for Windows AURA.
 181 PersistingImagesTable kPersistingImagesDesktopAura[] = {
 182   { PRS_THEME_FRAME_DESKTOP, IDR_THEME_FRAME_DESKTOP,
 183     "theme_frame" },
 184   { PRS_THEME_FRAME_INACTIVE_DESKTOP, IDR_THEME_FRAME_INACTIVE_DESKTOP,
 185     "theme_frame_inactive" },
 186   { PRS_THEME_FRAME_INCOGNITO_DESKTOP, IDR_THEME_FRAME_INCOGNITO_DESKTOP,
 187     "theme_frame_incognito" },
 188   { PRS_THEME_FRAME_INCOGNITO_INACTIVE_DESKTOP,
 189     IDR_THEME_FRAME_INCOGNITO_INACTIVE_DESKTOP,
 190     "theme_frame_incognito_inactive" },
 191   { PRS_THEME_TOOLBAR_DESKTOP, IDR_THEME_TOOLBAR_DESKTOP,
 192     "theme_toolbar" },
 193   { PRS_THEME_TAB_BACKGROUND_DESKTOP, IDR_THEME_TAB_BACKGROUND_DESKTOP,
 194     "theme_tab_background" },
 195   { PRS_THEME_TAB_BACKGROUND_INCOGNITO_DESKTOP,
 196     IDR_THEME_TAB_BACKGROUND_INCOGNITO_DESKTOP,
 197     "theme_tab_background_incognito" },
 198 };
 199 const size_t kPersistingImagesDesktopAuraLength =
 200     arraysize(kPersistingImagesDesktopAura);
 201 #endif
 202
 203 int GetPersistentIDByNameHelper(const std::string& key,
 204                                 const PersistingImagesTable* image_table,
 205                                 size_t image_table_size) {
 206   for (size_t i = 0; i < image_table_size; ++i) {
 207     if (image_table[i].key && LowerCaseEqualsASCII(key, image_table[i].key)) {
 208       return image_table[i].persistent_id;
 209     }
 210   }
 211   return -1;
 212 }
 213
 214 int GetPersistentIDByName(const std::string& key) {
 215   return GetPersistentIDByNameHelper(key,
 216                                      kPersistingImages,
 217                                      kPersistingImagesLength);
 218 }
 219
 220 int GetPersistentIDByIDR(int idr) {
 221   static std::map<int,int>* lookup_table = new std::map<int,int>();
 222   if (lookup_table->empty()) {
 223     for (size_t i = 0; i < kPersistingImagesLength; ++i) {
 224       int idr = kPersistingImages[i].idr_id;
 225       int prs_id = kPersistingImages[i].persistent_id;
 226       (*lookup_table)[idr] = prs_id;
 227     }
 228 #if defined(USE_ASH) && !defined(OS_CHROMEOS)
 229     for (size_t i = 0; i < kPersistingImagesDesktopAuraLength; ++i) {
 230       int idr = kPersistingImagesDesktopAura[i].idr_id;
 231       int prs_id = kPersistingImagesDesktopAura[i].persistent_id;
 232       (*lookup_table)[idr] = prs_id;
 233     }
 234 #endif
 235   }
 236   std::map<int,int>::iterator it = lookup_table->find(idr);
 237   return (it == lookup_table->end()) ? -1 : it->second;
 238 }
 239
 240 // Returns the maximum persistent id.
 241 int GetMaxPersistentId() {
 242   static int max_prs_id = -1;
 243   if (max_prs_id == -1) {
 244     for (size_t i = 0; i < kPersistingImagesLength; ++i) {
 245       if (kPersistingImages[i].persistent_id > max_prs_id)
 246         max_prs_id = kPersistingImages[i].persistent_id;
 247     }
 248 #if defined(USE_ASH) && !defined(OS_CHROMEOS)
 249     for (size_t i = 0; i < kPersistingImagesDesktopAuraLength; ++i) {
 250       if (kPersistingImagesDesktopAura[i].persistent_id > max_prs_id)
 251         max_prs_id = kPersistingImagesDesktopAura[i].persistent_id;
 252     }
 253 #endif
 254   }
 255   return max_prs_id;
 256 }
 257
 258 // Returns true if the scales in |input| match those in |expected|.
 259 // The order must match as the index is used in determining the raw id.
 260 bool InputScalesValid(const base::StringPiece& input,
 261                       const std::vector<ui::ScaleFactor>& expected) {
 262   size_t scales_size = static_cast<size_t>(input.size() / sizeof(float));
 263   if (scales_size != expected.size())
 264     return false;
 265   scoped_ptr<float[]> scales(new float[scales_size]);
 266   // Do a memcpy to avoid misaligned memory access.
 267   memcpy(scales.get(), input.data(), input.size());
 268   for (size_t index = 0; index < scales_size; ++index) {
 269     if (scales[index] != ui::GetScaleForScaleFactor(expected[index]))
 270       return false;
 271   }
 272   return true;
 273 }
 274
 275 // Returns |scale_factors| as a string to be written to disk.
 276 std::string GetScaleFactorsAsString(
 277     const std::vector<ui::ScaleFactor>& scale_factors) {
 278   scoped_ptr<float[]> scales(new float[scale_factors.size()]);
 279   for (size_t i = 0; i < scale_factors.size(); ++i)
 280     scales[i] = ui::GetScaleForScaleFactor(scale_factors[i]);
 281   std::string out_string = std::string(
 282       reinterpret_cast<const char*>(scales.get()),
 283       scale_factors.size() * sizeof(float));
 284   return out_string;
 285 }
 286
 287 struct StringToIntTable {
 288   const char* const key;
 289   ThemeProperties::OverwritableByUserThemeProperty id;
 290 };
 291
 292 // Strings used by themes to identify tints in the JSON.
 293 StringToIntTable kTintTable[] = {
 294   { "buttons", ThemeProperties::TINT_BUTTONS },
 295   { "frame", ThemeProperties::TINT_FRAME },
 296   { "frame_inactive", ThemeProperties::TINT_FRAME_INACTIVE },
 297   { "frame_incognito", ThemeProperties::TINT_FRAME_INCOGNITO },
 298   { "frame_incognito_inactive",
 299     ThemeProperties::TINT_FRAME_INCOGNITO_INACTIVE },
 300   { "background_tab", ThemeProperties::TINT_BACKGROUND_TAB },
 301 };
 302 const size_t kTintTableLength = arraysize(kTintTable);
 303
 304 // Strings used by themes to identify colors in the JSON.
 305 StringToIntTable kColorTable[] = {
 306   { "frame", ThemeProperties::COLOR_FRAME },
 307   { "frame_inactive", ThemeProperties::COLOR_FRAME_INACTIVE },
 308   { "frame_incognito", ThemeProperties::COLOR_FRAME_INCOGNITO },
 309   { "frame_incognito_inactive",
 310     ThemeProperties::COLOR_FRAME_INCOGNITO_INACTIVE },
 311   { "toolbar", ThemeProperties::COLOR_TOOLBAR },
 312   { "tab_text", ThemeProperties::COLOR_TAB_TEXT },
 313   { "tab_background_text", ThemeProperties::COLOR_BACKGROUND_TAB_TEXT },
 314   { "bookmark_text", ThemeProperties::COLOR_BOOKMARK_TEXT },
 315   { "ntp_background", ThemeProperties::COLOR_NTP_BACKGROUND },
 316   { "ntp_text", ThemeProperties::COLOR_NTP_TEXT },
 317   { "ntp_link", ThemeProperties::COLOR_NTP_LINK },
 318   { "ntp_link_underline", ThemeProperties::COLOR_NTP_LINK_UNDERLINE },
 319   { "ntp_header", ThemeProperties::COLOR_NTP_HEADER },
 320   { "ntp_section", ThemeProperties::COLOR_NTP_SECTION },
 321   { "ntp_section_text", ThemeProperties::COLOR_NTP_SECTION_TEXT },
 322   { "ntp_section_link", ThemeProperties::COLOR_NTP_SECTION_LINK },
 323   { "ntp_section_link_underline",
 324     ThemeProperties::COLOR_NTP_SECTION_LINK_UNDERLINE },
 325   { "button_background", ThemeProperties::COLOR_BUTTON_BACKGROUND },
 326 };
 327 const size_t kColorTableLength = arraysize(kColorTable);
 328
 329 // Strings used by themes to identify display properties keys in JSON.
 330 StringToIntTable kDisplayProperties[] = {
 331   { "ntp_background_alignment",
 332     ThemeProperties::NTP_BACKGROUND_ALIGNMENT },
 333   { "ntp_background_repeat", ThemeProperties::NTP_BACKGROUND_TILING },
 334   { "ntp_logo_alternate", ThemeProperties::NTP_LOGO_ALTERNATE },
 335 };
 336 const size_t kDisplayPropertiesSize = arraysize(kDisplayProperties);
 337
 338 int GetIntForString(const std::string& key,
 339                     StringToIntTable* table,
 340                     size_t table_length) {
 341   for (size_t i = 0; i < table_length; ++i) {
 342     if (LowerCaseEqualsASCII(key, table[i].key)) {
 343       return table[i].id;
 344     }
 345   }
 346
 347   return -1;
 348 }
 349
 350 struct IntToIntTable {
 351   int key;
 352   int value;
 353 };
 354
 355 // Mapping used in CreateFrameImages() to associate frame images with the
 356 // tint ID that should maybe be applied to it.
 357 IntToIntTable kFrameTintMap[] = {
 358   { PRS_THEME_FRAME, ThemeProperties::TINT_FRAME },
 359   { PRS_THEME_FRAME_INACTIVE, ThemeProperties::TINT_FRAME_INACTIVE },
 360   { PRS_THEME_FRAME_OVERLAY, ThemeProperties::TINT_FRAME },
 361   { PRS_THEME_FRAME_OVERLAY_INACTIVE,
 362     ThemeProperties::TINT_FRAME_INACTIVE },
 363   { PRS_THEME_FRAME_INCOGNITO, ThemeProperties::TINT_FRAME_INCOGNITO },
 364   { PRS_THEME_FRAME_INCOGNITO_INACTIVE,
 365     ThemeProperties::TINT_FRAME_INCOGNITO_INACTIVE },
 366 #if defined(USE_ASH) && !defined(OS_CHROMEOS)
 367   { PRS_THEME_FRAME_DESKTOP, ThemeProperties::TINT_FRAME },
 368   { PRS_THEME_FRAME_INACTIVE_DESKTOP, ThemeProperties::TINT_FRAME_INACTIVE },
 369   { PRS_THEME_FRAME_INCOGNITO_DESKTOP, ThemeProperties::TINT_FRAME_INCOGNITO },
 370   { PRS_THEME_FRAME_INCOGNITO_INACTIVE_DESKTOP,
 371     ThemeProperties::TINT_FRAME_INCOGNITO_INACTIVE },
 372 #endif
 373 };
 374
 375 // Mapping used in GenerateTabBackgroundImages() to associate what frame image
 376 // goes with which tab background.
 377 IntToIntTable kTabBackgroundMap[] = {
 378   { PRS_THEME_TAB_BACKGROUND, PRS_THEME_FRAME },
 379   { PRS_THEME_TAB_BACKGROUND_INCOGNITO, PRS_THEME_FRAME_INCOGNITO },
 380 #if defined(USE_ASH) && !defined(OS_CHROMEOS)
 381   { PRS_THEME_TAB_BACKGROUND_DESKTOP, PRS_THEME_FRAME_DESKTOP },
 382   { PRS_THEME_TAB_BACKGROUND_INCOGNITO_DESKTOP,
 383     PRS_THEME_FRAME_INCOGNITO_DESKTOP },
 384 #endif
 385 };
 386
 387 struct CropEntry {
 388   int prs_id;
 389
 390   // The maximum useful height of the image at |prs_id|.
 391   int max_height;
 392
 393   // Whether cropping the image at |prs_id| should be skipped on OSes which
 394   // have a frame border to the left and right of the web contents.
 395   // This should be true for images which can be used to decorate the border to
 396   // the left and the right of the web contents.
 397   bool skip_if_frame_border;
 398 };
 399
 400 // The images which should be cropped before being saved to the data pack. The
 401 // maximum heights are meant to be conservative as to give room for the UI to
 402 // change without the maximum heights having to be modified.
 403 // |kThemePackVersion| must be incremented if any of the maximum heights below
 404 // are modified.
 405 struct CropEntry kImagesToCrop[] = {
 406   { PRS_THEME_FRAME, 120, true },
 407   { PRS_THEME_FRAME_INACTIVE, 120, true },
 408   { PRS_THEME_FRAME_INCOGNITO, 120, true },
 409   { PRS_THEME_FRAME_INCOGNITO_INACTIVE, 120, true },
 410   { PRS_THEME_FRAME_OVERLAY, 120, true },
 411   { PRS_THEME_FRAME_OVERLAY_INACTIVE, 120, true },
 412   { PRS_THEME_TOOLBAR, 200, false },
 413   { PRS_THEME_BUTTON_BACKGROUND, 60, false },
 414   { PRS_THEME_WINDOW_CONTROL_BACKGROUND, 50, false },
 415 #if defined(USE_ASH) && !defined(OS_CHROMEOS)
 416   { PRS_THEME_TOOLBAR_DESKTOP, 200, false }
 417 #endif
 418 };
 419
 420
 421 // A list of images that don't need tinting or any other modification and can
 422 // be byte-copied directly into the finished DataPack. This should contain the
 423 // persistent IDs for all themeable image IDs that aren't in kFrameTintMap,
 424 // kTabBackgroundMap or kImagesToCrop.
 425 const int kPreloadIDs[] = {
 426   PRS_THEME_NTP_BACKGROUND,
 427   PRS_THEME_NTP_ATTRIBUTION,
 428 };
 429
 430 // Returns true if this OS uses a browser frame which has a non zero width to
 431 // the left and the right of the web contents.
 432 bool HasFrameBorder() {
 433 #if defined(OS_CHROMEOS) || defined(OS_MACOSX)
 434   return false;
 435 #else
 436   return true;
 437 #endif
 438 }
 439
 440 // Returns a piece of memory with the contents of the file |path|.
 441 base::RefCountedMemory* ReadFileData(const base::FilePath& path) {
 442   if (!path.empty()) {
 443     base::File file(path, base::File::FLAG_OPEN | base::File::FLAG_READ);
 444     if (file.IsValid()) {
 445       int64 length = file.GetLength();
 446       if (length > 0 && length < INT_MAX) {
 447         int size = static_cast<int>(length);
 448         std::vector<unsigned char> raw_data;
 449         raw_data.resize(size);
 450         char* data = reinterpret_cast<char*>(&(raw_data.front()));
 451         if (file.ReadAtCurrentPos(data, size) == length)
 452           return base::RefCountedBytes::TakeVector(&raw_data);
 453       }
 454     }
 455   }
 456
 457   return NULL;
 458 }
 459
 460 // Shifts an image's HSL values. The caller is responsible for deleting
 461 // the returned image.
 462 gfx::Image CreateHSLShiftedImage(const gfx::Image& image,
 463                                  const color_utils::HSL& hsl_shift) {
 464   const gfx::ImageSkia* src_image = image.ToImageSkia();
 465   return gfx::Image(gfx::ImageSkiaOperations::CreateHSLShiftedImage(
 466       *src_image, hsl_shift));
 467 }
 468
 469 // Computes a bitmap at one scale from a bitmap at a different scale.
 470 SkBitmap CreateLowQualityResizedBitmap(const SkBitmap& source_bitmap,
 471                                        ui::ScaleFactor source_scale_factor,
 472                                        ui::ScaleFactor desired_scale_factor) {
 473   gfx::Size scaled_size = gfx::ToCeiledSize(
 474       gfx::ScaleSize(gfx::Size(source_bitmap.width(),
 475                                source_bitmap.height()),
 476                      ui::GetScaleForScaleFactor(desired_scale_factor) /
 477                      ui::GetScaleForScaleFactor(source_scale_factor)));
 478   SkBitmap scaled_bitmap;
 479   scaled_bitmap.allocN32Pixels(scaled_size.width(), scaled_size.height());
 480   scaled_bitmap.eraseARGB(0, 0, 0, 0);
 481   SkCanvas canvas(scaled_bitmap);
 482   SkRect scaled_bounds = RectToSkRect(gfx::Rect(scaled_size));
 483   // Note(oshima): The following scaling code doesn't work with
 484   // a mask image.
 485   canvas.drawBitmapRect(source_bitmap, NULL, scaled_bounds);
 486   return scaled_bitmap;
 487 }
 488
 489 // A ImageSkiaSource that scales 100P image to the target scale factor
 490 // if the ImageSkiaRep for the target scale factor isn't available.
 491 class ThemeImageSource: public gfx::ImageSkiaSource {
 492  public:
 493   explicit ThemeImageSource(const gfx::ImageSkia& source) : source_(source) {
 494   }
 495   ~ThemeImageSource() override {}
 496
 497   gfx::ImageSkiaRep GetImageForScale(float scale) override {
 498     if (source_.HasRepresentation(scale))
 499       return source_.GetRepresentation(scale);
 500     const gfx::ImageSkiaRep& rep_100p = source_.GetRepresentation(1.0f);
 501     SkBitmap scaled_bitmap = CreateLowQualityResizedBitmap(
 502         rep_100p.sk_bitmap(),
 503         ui::SCALE_FACTOR_100P,
 504         ui::GetSupportedScaleFactor(scale));
 505     return gfx::ImageSkiaRep(scaled_bitmap, scale);
 506   }
 507
 508  private:
 509   const gfx::ImageSkia source_;
 510
 511   DISALLOW_COPY_AND_ASSIGN(ThemeImageSource);
 512 };
 513
 514 // An ImageSkiaSource that delays decoding PNG data into bitmaps until
 515 // needed. Missing data for a scale factor is computed by scaling data for an
 516 // available scale factor. Computed bitmaps are stored for future look up.
 517 class ThemeImagePngSource : public gfx::ImageSkiaSource {
 518  public:
 519   typedef std::map<ui::ScaleFactor,
 520                    scoped_refptr<base::RefCountedMemory> > PngMap;
 521
 522   explicit ThemeImagePngSource(const PngMap& png_map) : png_map_(png_map) {}
 523
 524   ~ThemeImagePngSource() override {}
 525
 526  private:
 527   gfx::ImageSkiaRep GetImageForScale(float scale) override {
 528     ui::ScaleFactor scale_factor = ui::GetSupportedScaleFactor(scale);
 529     // Look up the bitmap for |scale factor| in the bitmap map. If found
 530     // return it.
 531     BitmapMap::const_iterator exact_bitmap_it = bitmap_map_.find(scale_factor);
 532     if (exact_bitmap_it != bitmap_map_.end())
 533       return gfx::ImageSkiaRep(exact_bitmap_it->second, scale);
 534
 535     // Look up the raw PNG data for |scale_factor| in the png map. If found,
 536     // decode it, store the result in the bitmap map and return it.
 537     PngMap::const_iterator exact_png_it = png_map_.find(scale_factor);
 538     if (exact_png_it != png_map_.end()) {
 539       SkBitmap bitmap;
 540       if (!gfx::PNGCodec::Decode(exact_png_it->second->front(),
 541                                  exact_png_it->second->size(),
 542                                  &bitmap)) {
 543         NOTREACHED();
 544         return gfx::ImageSkiaRep();
 545       }
 546       bitmap_map_[scale_factor] = bitmap;
 547       return gfx::ImageSkiaRep(bitmap, scale);
 548     }
 549
 550     // Find an available PNG for another scale factor. We want to use the
 551     // highest available scale factor.
 552     PngMap::const_iterator available_png_it = png_map_.end();
 553     for (PngMap::const_iterator png_it = png_map_.begin();
 554          png_it != png_map_.end(); ++png_it) {
 555       if (available_png_it == png_map_.end() ||
 556           ui::GetScaleForScaleFactor(png_it->first) >
 557           ui::GetScaleForScaleFactor(available_png_it->first)) {
 558         available_png_it = png_it;
 559       }
 560     }
 561     if (available_png_it == png_map_.end())
 562       return gfx::ImageSkiaRep();
 563     ui::ScaleFactor available_scale_factor = available_png_it->first;
 564
 565     // Look up the bitmap for |available_scale_factor| in the bitmap map.
 566     // If not found, decode the corresponging png data, store the result
 567     // in the bitmap map.
 568     BitmapMap::const_iterator available_bitmap_it =
 569         bitmap_map_.find(available_scale_factor);
 570     if (available_bitmap_it == bitmap_map_.end()) {
 571       SkBitmap available_bitmap;
 572       if (!gfx::PNGCodec::Decode(available_png_it->second->front(),
 573                                  available_png_it->second->size(),
 574                                  &available_bitmap)) {
 575         NOTREACHED();
 576         return gfx::ImageSkiaRep();
 577       }
 578       bitmap_map_[available_scale_factor] = available_bitmap;
 579       available_bitmap_it = bitmap_map_.find(available_scale_factor);
 580     }
 581
 582     // Scale the available bitmap to the desired scale factor, store the result
 583     // in the bitmap map and return it.
 584     SkBitmap scaled_bitmap = CreateLowQualityResizedBitmap(
 585         available_bitmap_it->second,
 586         available_scale_factor,
 587         scale_factor);
 588     bitmap_map_[scale_factor] = scaled_bitmap;
 589     return gfx::ImageSkiaRep(scaled_bitmap, scale);
 590   }
 591
 592   PngMap png_map_;
 593
 594   typedef std::map<ui::ScaleFactor, SkBitmap> BitmapMap;
 595   BitmapMap bitmap_map_;
 596
 597   DISALLOW_COPY_AND_ASSIGN(ThemeImagePngSource);
 598 };
 599
 600 class TabBackgroundImageSource: public gfx::CanvasImageSource {
 601  public:
 602   TabBackgroundImageSource(const gfx::ImageSkia& image_to_tint,
 603                            const gfx::ImageSkia& overlay,
 604                            const color_utils::HSL& hsl_shift,
 605                            int vertical_offset)
 606       : gfx::CanvasImageSource(image_to_tint.size(), false),
 607         image_to_tint_(image_to_tint),
 608         overlay_(overlay),
 609         hsl_shift_(hsl_shift),
 610         vertical_offset_(vertical_offset) {
 611   }
 612
 613   ~TabBackgroundImageSource() override {}
 614
 615   // Overridden from CanvasImageSource:
 616   void Draw(gfx::Canvas* canvas) override {
 617     gfx::ImageSkia bg_tint =
 618         gfx::ImageSkiaOperations::CreateHSLShiftedImage(image_to_tint_,
 619             hsl_shift_);
 620     canvas->TileImageInt(bg_tint, 0, vertical_offset_, 0, 0,
 621         size().width(), size().height());
 622
 623     // If they've provided a custom image, overlay it.
 624     if (!overlay_.isNull()) {
 625       canvas->TileImageInt(overlay_, 0, 0, size().width(),
 626                            overlay_.height());
 627     }
 628   }
 629
 630  private:
 631   const gfx::ImageSkia image_to_tint_;
 632   const gfx::ImageSkia overlay_;
 633   const color_utils::HSL hsl_shift_;
 634   const int vertical_offset_;
 635
 636   DISALLOW_COPY_AND_ASSIGN(TabBackgroundImageSource);
 637 };
 638
 639 }  // namespace
 640
 641 BrowserThemePack::~BrowserThemePack() {
 642   if (!data_pack_.get()) {
 643     delete header_;
 644     delete [] tints_;
 645     delete [] colors_;
 646     delete [] display_properties_;
 647     delete [] source_images_;
 648   }
 649 }
 650
 651 // static
 652 scoped_refptr<BrowserThemePack> BrowserThemePack::BuildFromExtension(
 653     const Extension* extension) {
 654   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 655   DCHECK(extension);
 656   DCHECK(extension->is_theme());
 657
 658   scoped_refptr<BrowserThemePack> pack(new BrowserThemePack);
 659   pack->BuildHeader(extension);
 660   pack->BuildTintsFromJSON(extensions::ThemeInfo::GetTints(extension));
 661   pack->BuildColorsFromJSON(extensions::ThemeInfo::GetColors(extension));
 662   pack->BuildDisplayPropertiesFromJSON(
 663       extensions::ThemeInfo::GetDisplayProperties(extension));
 664
 665   // Builds the images. (Image building is dependent on tints).
 666   FilePathMap file_paths;
 667   pack->ParseImageNamesFromJSON(
 668       extensions::ThemeInfo::GetImages(extension),
 669       extension->path(),
 670       &file_paths);
 671   pack->BuildSourceImagesArray(file_paths);
 672
 673   if (!pack->LoadRawBitmapsTo(file_paths, &pack->images_on_ui_thread_))
 674     return NULL;
 675
 676   pack->CreateImages(&pack->images_on_ui_thread_);
 677
 678   // Make sure the |images_on_file_thread_| has bitmaps for supported
 679   // scale factors before passing to FILE thread.
 680   pack->images_on_file_thread_ = pack->images_on_ui_thread_;
 681   for (ImageCache::iterator it = pack->images_on_file_thread_.begin();
 682        it != pack->images_on_file_thread_.end(); ++it) {
 683     gfx::ImageSkia* image_skia =
 684         const_cast<gfx::ImageSkia*>(it->second.ToImageSkia());
 685     image_skia->MakeThreadSafe();
 686   }
 687
 688   // Set ThemeImageSource on |images_on_ui_thread_| to resample the source
 689   // image if a caller of BrowserThemePack::GetImageNamed() requests an
 690   // ImageSkiaRep for a scale factor not specified by the theme author.
 691   // Callers of BrowserThemePack::GetImageNamed() to be able to retrieve
 692   // ImageSkiaReps for all supported scale factors.
 693   for (ImageCache::iterator it = pack->images_on_ui_thread_.begin();
 694        it != pack->images_on_ui_thread_.end(); ++it) {
 695     const gfx::ImageSkia source_image_skia = it->second.AsImageSkia();
 696     ThemeImageSource* source = new ThemeImageSource(source_image_skia);
 697     // image_skia takes ownership of source.
 698     gfx::ImageSkia image_skia(source, source_image_skia.size());
 699     it->second = gfx::Image(image_skia);
 700   }
 701
 702   // Generate raw images (for new-tab-page attribution and background) for
 703   // any missing scale from an available scale image.
 704   for (size_t i = 0; i < arraysize(kPreloadIDs); ++i) {
 705     pack->GenerateRawImageForAllSupportedScales(kPreloadIDs[i]);
 706   }
 707
 708   // The BrowserThemePack is now in a consistent state.
 709   return pack;
 710 }
 711
 712 // static
 713 scoped_refptr<BrowserThemePack> BrowserThemePack::BuildFromDataPack(
 714     const base::FilePath& path, const std::string& expected_id) {
 715   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 716   // Allow IO on UI thread due to deep-seated theme design issues.
 717   // (see http://crbug.com/80206)
 718   base::ThreadRestrictions::ScopedAllowIO allow_io;
 719   scoped_refptr<BrowserThemePack> pack(new BrowserThemePack);
 720   // Scale factor parameter is moot as data pack has image resources for all
 721   // supported scale factors.
 722   pack->data_pack_.reset(
 723       new ui::DataPack(ui::SCALE_FACTOR_NONE));
 724
 725   if (!pack->data_pack_->LoadFromPath(path)) {
 726     LOG(ERROR) << "Failed to load theme data pack.";
 727     return NULL;
 728   }
 729
 730   base::StringPiece pointer;
 731   if (!pack->data_pack_->GetStringPiece(kHeaderID, &pointer))
 732     return NULL;
 733   pack->header_ = reinterpret_cast<BrowserThemePackHeader*>(const_cast<char*>(
 734       pointer.data()));
 735
 736   if (pack->header_->version != kThemePackVersion) {
 737     DLOG(ERROR) << "BuildFromDataPack failure! Version mismatch!";
 738     return NULL;
 739   }
 740   // TODO(erg): Check endianess once DataPack works on the other endian.
 741   std::string theme_id(reinterpret_cast<char*>(pack->header_->theme_id),
 742                        crx_file::id_util::kIdSize);
 743   std::string truncated_id = expected_id.substr(0, crx_file::id_util::kIdSize);
 744   if (theme_id != truncated_id) {
 745     DLOG(ERROR) << "Wrong id: " << theme_id << " vs " << expected_id;
 746     return NULL;
 747   }
 748
 749   if (!pack->data_pack_->GetStringPiece(kTintsID, &pointer))
 750     return NULL;
 751   pack->tints_ = reinterpret_cast<TintEntry*>(const_cast<char*>(
 752       pointer.data()));
 753
 754   if (!pack->data_pack_->GetStringPiece(kColorsID, &pointer))
 755     return NULL;
 756   pack->colors_ =
 757       reinterpret_cast<ColorPair*>(const_cast<char*>(pointer.data()));
 758
 759   if (!pack->data_pack_->GetStringPiece(kDisplayPropertiesID, &pointer))
 760     return NULL;
 761   pack->display_properties_ = reinterpret_cast<DisplayPropertyPair*>(
 762       const_cast<char*>(pointer.data()));
 763
 764   if (!pack->data_pack_->GetStringPiece(kSourceImagesID, &pointer))
 765     return NULL;
 766   pack->source_images_ = reinterpret_cast<int*>(
 767       const_cast<char*>(pointer.data()));
 768
 769   if (!pack->data_pack_->GetStringPiece(kScaleFactorsID, &pointer))
 770     return NULL;
 771
 772   if (!InputScalesValid(pointer, pack->scale_factors_)) {
 773     DLOG(ERROR) << "BuildFromDataPack failure! The pack scale factors differ "
 774                 << "from those supported by platform.";
 775     return NULL;
 776   }
 777   return pack;
 778 }
 779
 780 // static
 781 bool BrowserThemePack::IsPersistentImageID(int id) {
 782   for (size_t i = 0; i < kPersistingImagesLength; ++i)
 783     if (kPersistingImages[i].idr_id == id)
 784       return true;
 785
 786 #if defined(USE_ASH) && !defined(OS_CHROMEOS)
 787   for (size_t i = 0; i < kPersistingImagesDesktopAuraLength; ++i)
 788     if (kPersistingImagesDesktopAura[i].idr_id == id)
 789       return true;
 790 #endif
 791
 792   return false;
 793 }
 794
 795 bool BrowserThemePack::WriteToDisk(const base::FilePath& path) const {
 796   // Add resources for each of the property arrays.
 797   RawDataForWriting resources;
 798   resources[kHeaderID] = base::StringPiece(
 799       reinterpret_cast<const char*>(header_), sizeof(BrowserThemePackHeader));
 800   resources[kTintsID] = base::StringPiece(
 801       reinterpret_cast<const char*>(tints_),
 802       sizeof(TintEntry[kTintTableLength]));
 803   resources[kColorsID] = base::StringPiece(
 804       reinterpret_cast<const char*>(colors_),
 805       sizeof(ColorPair[kColorTableLength]));
 806   resources[kDisplayPropertiesID] = base::StringPiece(
 807       reinterpret_cast<const char*>(display_properties_),
 808       sizeof(DisplayPropertyPair[kDisplayPropertiesSize]));
 809
 810   int source_count = 1;
 811   int* end = source_images_;
 812   for (; *end != -1 ; end++)
 813     source_count++;
 814   resources[kSourceImagesID] = base::StringPiece(
 815       reinterpret_cast<const char*>(source_images_),
 816       source_count * sizeof(*source_images_));
 817
 818   // Store results of GetScaleFactorsAsString() in std::string as
 819   // base::StringPiece does not copy data in constructor.
 820   std::string scale_factors_string = GetScaleFactorsAsString(scale_factors_);
 821   resources[kScaleFactorsID] = scale_factors_string;
 822
 823   AddRawImagesTo(image_memory_, &resources);
 824
 825   RawImages reencoded_images;
 826   RepackImages(images_on_file_thread_, &reencoded_images);
 827   AddRawImagesTo(reencoded_images, &resources);
 828
 829   return ui::DataPack::WritePack(path, resources, ui::DataPack::BINARY);
 830 }
 831
 832 bool BrowserThemePack::GetTint(int id, color_utils::HSL* hsl) const {
 833   if (tints_) {
 834     for (size_t i = 0; i < kTintTableLength; ++i) {
 835       if (tints_[i].id == id) {
 836         hsl->h = tints_[i].h;
 837         hsl->s = tints_[i].s;
 838         hsl->l = tints_[i].l;
 839         return true;
 840       }
 841     }
 842   }
 843
 844   return false;
 845 }
 846
 847 bool BrowserThemePack::GetColor(int id, SkColor* color) const {
 848   if (colors_) {
 849     for (size_t i = 0; i < kColorTableLength; ++i) {
 850       if (colors_[i].id == id) {
 851         *color = colors_[i].color;
 852         return true;
 853       }
 854     }
 855   }
 856
 857   return false;
 858 }
 859
 860 bool BrowserThemePack::GetDisplayProperty(int id, int* result) const {
 861   if (display_properties_) {
 862     for (size_t i = 0; i < kDisplayPropertiesSize; ++i) {
 863       if (display_properties_[i].id == id) {
 864         *result = display_properties_[i].property;
 865         return true;
 866       }
 867     }
 868   }
 869
 870   return false;
 871 }
 872
 873 gfx::Image BrowserThemePack::GetImageNamed(int idr_id) {
 874   int prs_id = GetPersistentIDByIDR(idr_id);
 875   if (prs_id == -1)
 876     return gfx::Image();
 877
 878   // Check if the image is cached.
 879   ImageCache::const_iterator image_iter = images_on_ui_thread_.find(prs_id);
 880   if (image_iter != images_on_ui_thread_.end())
 881     return image_iter->second;
 882
 883   ThemeImagePngSource::PngMap png_map;
 884   for (size_t i = 0; i < scale_factors_.size(); ++i) {
 885     scoped_refptr<base::RefCountedMemory> memory =
 886         GetRawData(idr_id, scale_factors_[i]);
 887     if (memory.get())
 888       png_map[scale_factors_[i]] = memory;
 889   }
 890   if (!png_map.empty()) {
 891     gfx::ImageSkia image_skia(new ThemeImagePngSource(png_map), 1.0f);
 892     // |image_skia| takes ownership of ThemeImagePngSource.
 893     gfx::Image ret = gfx::Image(image_skia);
 894     images_on_ui_thread_[prs_id] = ret;
 895     return ret;
 896   }
 897
 898   return gfx::Image();
 899 }
 900
 901 base::RefCountedMemory* BrowserThemePack::GetRawData(
 902     int idr_id,
 903     ui::ScaleFactor scale_factor) const {
 904   base::RefCountedMemory* memory = NULL;
 905   int prs_id = GetPersistentIDByIDR(idr_id);
 906   int raw_id = GetRawIDByPersistentID(prs_id, scale_factor);
 907
 908   if (raw_id != -1) {
 909     if (data_pack_.get()) {
 910       memory = data_pack_->GetStaticMemory(raw_id);
 911     } else {
 912       RawImages::const_iterator it = image_memory_.find(raw_id);
 913       if (it != image_memory_.end()) {
 914         memory = it->second.get();
 915       }
 916     }
 917   }
 918
 919   return memory;
 920 }
 921
 922 bool BrowserThemePack::HasCustomImage(int idr_id) const {
 923   int prs_id = GetPersistentIDByIDR(idr_id);
 924   if (prs_id == -1)
 925     return false;
 926
 927   int* img = source_images_;
 928   for (; *img != -1; ++img) {
 929     if (*img == prs_id)
 930       return true;
 931   }
 932
 933   return false;
 934 }
 935
 936 // private:
 937
 938 BrowserThemePack::BrowserThemePack()
 939     : CustomThemeSupplier(EXTENSION),
 940       header_(NULL),
 941       tints_(NULL),
 942       colors_(NULL),
 943       display_properties_(NULL),
 944       source_images_(NULL) {
 945   scale_factors_ = ui::GetSupportedScaleFactors();
 946   // On Windows HiDPI SCALE_FACTOR_100P may not be supported by default.
 947   if (std::find(scale_factors_.begin(), scale_factors_.end(),
 948                 ui::SCALE_FACTOR_100P) == scale_factors_.end()) {
 949     scale_factors_.push_back(ui::SCALE_FACTOR_100P);
 950   }
 951 }
 952
 953 void BrowserThemePack::BuildHeader(const Extension* extension) {
 954   header_ = new BrowserThemePackHeader;
 955   header_->version = kThemePackVersion;
 956
 957   // TODO(erg): Need to make this endian safe on other computers. Prerequisite
 958   // is that ui::DataPack removes this same check.
 959 #if defined(__BYTE_ORDER)
 960   // Linux check
 961   static_assert(__BYTE_ORDER == __LITTLE_ENDIAN,
 962                 "datapack assumes little endian");
 963 #elif defined(__BIG_ENDIAN__)
 964   // Mac check
 965   #error DataPack assumes little endian
 966 #endif
 967   header_->little_endian = 1;
 968
 969   const std::string& id = extension->id();
 970   memcpy(header_->theme_id, id.c_str(), crx_file::id_util::kIdSize);
 971 }
 972
 973 void BrowserThemePack::BuildTintsFromJSON(
 974     const base::DictionaryValue* tints_value) {
 975   tints_ = new TintEntry[kTintTableLength];
 976   for (size_t i = 0; i < kTintTableLength; ++i) {
 977     tints_[i].id = -1;
 978     tints_[i].h = -1;
 979     tints_[i].s = -1;
 980     tints_[i].l = -1;
 981   }
 982
 983   if (!tints_value)
 984     return;
 985
 986   // Parse the incoming data from |tints_value| into an intermediary structure.
 987   std::map<int, color_utils::HSL> temp_tints;
 988   for (base::DictionaryValue::Iterator iter(*tints_value); !iter.IsAtEnd();
 989        iter.Advance()) {
 990     const base::ListValue* tint_list;
 991     if (iter.value().GetAsList(&tint_list) &&
 992         (tint_list->GetSize() == 3)) {
 993       color_utils::HSL hsl = { -1, -1, -1 };
 994
 995       if (tint_list->GetDouble(0, &hsl.h) &&
 996           tint_list->GetDouble(1, &hsl.s) &&
 997           tint_list->GetDouble(2, &hsl.l)) {
 998         MakeHSLShiftValid(&hsl);
 999         int id = GetIntForString(iter.key(), kTintTable, kTintTableLength);
1000         if (id != -1) {
1001           temp_tints[id] = hsl;
1002         }
1003       }
1004     }
1005   }
1006
1007   // Copy data from the intermediary data structure to the array.
1008   size_t count = 0;
1009   for (std::map<int, color_utils::HSL>::const_iterator it =
1010            temp_tints.begin();
1011        it != temp_tints.end() && count < kTintTableLength;
1012        ++it, ++count) {
1013     tints_[count].id = it->first;
1014     tints_[count].h = it->second.h;
1015     tints_[count].s = it->second.s;
1016     tints_[count].l = it->second.l;
1017   }
1018 }
1019
1020 void BrowserThemePack::BuildColorsFromJSON(
1021     const base::DictionaryValue* colors_value) {
1022   colors_ = new ColorPair[kColorTableLength];
1023   for (size_t i = 0; i < kColorTableLength; ++i) {
1024     colors_[i].id = -1;
1025     colors_[i].color = SkColorSetRGB(0, 0, 0);
1026   }
1027
1028   std::map<int, SkColor> temp_colors;
1029   if (colors_value)
1030     ReadColorsFromJSON(colors_value, &temp_colors);
1031   GenerateMissingColors(&temp_colors);
1032
1033   // Copy data from the intermediary data structure to the array.
1034   size_t count = 0;
1035   for (std::map<int, SkColor>::const_iterator it = temp_colors.begin();
1036        it != temp_colors.end() && count < kColorTableLength; ++it, ++count) {
1037     colors_[count].id = it->first;
1038     colors_[count].color = it->second;
1039   }
1040 }
1041
1042 void BrowserThemePack::ReadColorsFromJSON(
1043     const base::DictionaryValue* colors_value,
1044     std::map<int, SkColor>* temp_colors) {
1045   // Parse the incoming data from |colors_value| into an intermediary structure.
1046   for (base::DictionaryValue::Iterator iter(*colors_value); !iter.IsAtEnd();
1047        iter.Advance()) {
1048     const base::ListValue* color_list;
1049     if (iter.value().GetAsList(&color_list) &&
1050         ((color_list->GetSize() == 3) || (color_list->GetSize() == 4))) {
1051       SkColor color = SK_ColorWHITE;
1052       int r, g, b;
1053       if (color_list->GetInteger(0, &r) &&
1054           color_list->GetInteger(1, &g) &&
1055           color_list->GetInteger(2, &b)) {
1056         if (color_list->GetSize() == 4) {
1057           double alpha;
1058           int alpha_int;
1059           if (color_list->GetDouble(3, &alpha)) {
1060             color = SkColorSetARGB(static_cast<int>(alpha * 255), r, g, b);
1061           } else if (color_list->GetInteger(3, &alpha_int) &&
1062                      (alpha_int == 0 || alpha_int == 1)) {
1063             color = SkColorSetARGB(alpha_int ? 255 : 0, r, g, b);
1064           } else {
1065             // Invalid entry for part 4.
1066             continue;
1067           }
1068         } else {
1069           color = SkColorSetRGB(r, g, b);
1070         }
1071
1072         int id = GetIntForString(iter.key(), kColorTable, kColorTableLength);
1073         if (id != -1) {
1074           (*temp_colors)[id] = color;
1075         }
1076       }
1077     }
1078   }
1079 }
1080
1081 void BrowserThemePack::GenerateMissingColors(
1082     std::map<int, SkColor>* colors) {
1083   // Generate link colors, if missing. (See GetColor()).
1084   if (!colors->count(ThemeProperties::COLOR_NTP_HEADER) &&
1085       colors->count(ThemeProperties::COLOR_NTP_SECTION)) {
1086     (*colors)[ThemeProperties::COLOR_NTP_HEADER] =
1087         (*colors)[ThemeProperties::COLOR_NTP_SECTION];
1088   }
1089
1090   if (!colors->count(ThemeProperties::COLOR_NTP_SECTION_LINK_UNDERLINE) &&
1091       colors->count(ThemeProperties::COLOR_NTP_SECTION_LINK)) {
1092     SkColor color_section_link =
1093         (*colors)[ThemeProperties::COLOR_NTP_SECTION_LINK];
1094     (*colors)[ThemeProperties::COLOR_NTP_SECTION_LINK_UNDERLINE] =
1095         SkColorSetA(color_section_link, SkColorGetA(color_section_link) / 3);
1096   }
1097
1098   if (!colors->count(ThemeProperties::COLOR_NTP_LINK_UNDERLINE) &&
1099       colors->count(ThemeProperties::COLOR_NTP_LINK)) {
1100     SkColor color_link = (*colors)[ThemeProperties::COLOR_NTP_LINK];
1101     (*colors)[ThemeProperties::COLOR_NTP_LINK_UNDERLINE] =
1102         SkColorSetA(color_link, SkColorGetA(color_link) / 3);
1103   }
1104
1105   // Generate frame colors, if missing. (See GenerateFrameColors()).
1106   SkColor frame;
1107   std::map<int, SkColor>::const_iterator it =
1108       colors->find(ThemeProperties::COLOR_FRAME);
1109   if (it != colors->end()) {
1110     frame = it->second;
1111   } else {
1112     frame = ThemeProperties::GetDefaultColor(
1113         ThemeProperties::COLOR_FRAME);
1114   }
1115
1116   if (!colors->count(ThemeProperties::COLOR_FRAME)) {
1117     (*colors)[ThemeProperties::COLOR_FRAME] =
1118         HSLShift(frame, GetTintInternal(ThemeProperties::TINT_FRAME));
1119   }
1120   if (!colors->count(ThemeProperties::COLOR_FRAME_INACTIVE)) {
1121     (*colors)[ThemeProperties::COLOR_FRAME_INACTIVE] =
1122         HSLShift(frame, GetTintInternal(
1123             ThemeProperties::TINT_FRAME_INACTIVE));
1124   }
1125   if (!colors->count(ThemeProperties::COLOR_FRAME_INCOGNITO)) {
1126     (*colors)[ThemeProperties::COLOR_FRAME_INCOGNITO] =
1127         HSLShift(frame, GetTintInternal(
1128             ThemeProperties::TINT_FRAME_INCOGNITO));
1129   }
1130   if (!colors->count(ThemeProperties::COLOR_FRAME_INCOGNITO_INACTIVE)) {
1131     (*colors)[ThemeProperties::COLOR_FRAME_INCOGNITO_INACTIVE] =
1132         HSLShift(frame, GetTintInternal(
1133             ThemeProperties::TINT_FRAME_INCOGNITO_INACTIVE));
1134   }
1135 }
1136
1137 void BrowserThemePack::BuildDisplayPropertiesFromJSON(
1138     const base::DictionaryValue* display_properties_value) {
1139   display_properties_ = new DisplayPropertyPair[kDisplayPropertiesSize];
1140   for (size_t i = 0; i < kDisplayPropertiesSize; ++i) {
1141     display_properties_[i].id = -1;
1142     display_properties_[i].property = 0;
1143   }
1144
1145   if (!display_properties_value)
1146     return;
1147
1148   std::map<int, int> temp_properties;
1149   for (base::DictionaryValue::Iterator iter(*display_properties_value);
1150        !iter.IsAtEnd(); iter.Advance()) {
1151     int property_id = GetIntForString(iter.key(), kDisplayProperties,
1152                                       kDisplayPropertiesSize);
1153     switch (property_id) {
1154       case ThemeProperties::NTP_BACKGROUND_ALIGNMENT: {
1155         std::string val;
1156         if (iter.value().GetAsString(&val)) {
1157           temp_properties[ThemeProperties::NTP_BACKGROUND_ALIGNMENT] =
1158               ThemeProperties::StringToAlignment(val);
1159         }
1160         break;
1161       }
1162       case ThemeProperties::NTP_BACKGROUND_TILING: {
1163         std::string val;
1164         if (iter.value().GetAsString(&val)) {
1165           temp_properties[ThemeProperties::NTP_BACKGROUND_TILING] =
1166               ThemeProperties::StringToTiling(val);
1167         }
1168         break;
1169       }
1170       case ThemeProperties::NTP_LOGO_ALTERNATE: {
1171         int val = 0;
1172         if (iter.value().GetAsInteger(&val))
1173           temp_properties[ThemeProperties::NTP_LOGO_ALTERNATE] = val;
1174         break;
1175       }
1176     }
1177   }
1178
1179   // Copy data from the intermediary data structure to the array.
1180   size_t count = 0;
1181   for (std::map<int, int>::const_iterator it = temp_properties.begin();
1182        it != temp_properties.end() && count < kDisplayPropertiesSize;
1183        ++it, ++count) {
1184     display_properties_[count].id = it->first;
1185     display_properties_[count].property = it->second;
1186   }
1187 }
1188
1189 void BrowserThemePack::ParseImageNamesFromJSON(
1190     const base::DictionaryValue* images_value,
1191     const base::FilePath& images_path,
1192     FilePathMap* file_paths) const {
1193   if (!images_value)
1194     return;
1195
1196   for (base::DictionaryValue::Iterator iter(*images_value); !iter.IsAtEnd();
1197        iter.Advance()) {
1198     if (iter.value().IsType(base::Value::TYPE_DICTIONARY)) {
1199       const base::DictionaryValue* inner_value = NULL;
1200       if (iter.value().GetAsDictionary(&inner_value)) {
1201         for (base::DictionaryValue::Iterator inner_iter(*inner_value);
1202              !inner_iter.IsAtEnd();
1203              inner_iter.Advance()) {
1204           std::string name;
1205           ui::ScaleFactor scale_factor = ui::SCALE_FACTOR_NONE;
1206           if (GetScaleFactorFromManifestKey(inner_iter.key(), &scale_factor) &&
1207               inner_iter.value().IsType(base::Value::TYPE_STRING) &&
1208               inner_iter.value().GetAsString(&name)) {
1209             AddFileAtScaleToMap(iter.key(),
1210                                 scale_factor,
1211                                 images_path.AppendASCII(name),
1212                                 file_paths);
1213           }
1214         }
1215       }
1216     } else if (iter.value().IsType(base::Value::TYPE_STRING)) {
1217       std::string name;
1218       if (iter.value().GetAsString(&name)) {
1219         AddFileAtScaleToMap(iter.key(),
1220                             ui::SCALE_FACTOR_100P,
1221                             images_path.AppendASCII(name),
1222                             file_paths);
1223       }
1224     }
1225   }
1226 }
1227
1228 void BrowserThemePack::AddFileAtScaleToMap(const std::string& image_name,
1229                                            ui::ScaleFactor scale_factor,
1230                                            const base::FilePath& image_path,
1231                                            FilePathMap* file_paths) const {
1232   int id = GetPersistentIDByName(image_name);
1233   if (id != -1)
1234     (*file_paths)[id][scale_factor] = image_path;
1235 #if defined(USE_ASH) && !defined(OS_CHROMEOS)
1236   id = GetPersistentIDByNameHelper(image_name,
1237                                    kPersistingImagesDesktopAura,
1238                                    kPersistingImagesDesktopAuraLength);
1239   if (id != -1)
1240     (*file_paths)[id][scale_factor] = image_path;
1241 #endif
1242 }
1243
1244 void BrowserThemePack::BuildSourceImagesArray(const FilePathMap& file_paths) {
1245   std::vector<int> ids;
1246   for (FilePathMap::const_iterator it = file_paths.begin();
1247        it != file_paths.end(); ++it) {
1248     ids.push_back(it->first);
1249   }
1250
1251   source_images_ = new int[ids.size() + 1];
1252   std::copy(ids.begin(), ids.end(), source_images_);
1253   source_images_[ids.size()] = -1;
1254 }
1255
1256 bool BrowserThemePack::LoadRawBitmapsTo(
1257     const FilePathMap& file_paths,
1258     ImageCache* image_cache) {
1259   // Themes should be loaded on the file thread, not the UI thread.
1260   // http://crbug.com/61838
1261   base::ThreadRestrictions::ScopedAllowIO allow_io;
1262
1263   for (FilePathMap::const_iterator it = file_paths.begin();
1264        it != file_paths.end(); ++it) {
1265     int prs_id = it->first;
1266     // Some images need to go directly into |image_memory_|. No modification is
1267     // necessary or desirable.
1268     bool is_copyable = false;
1269     for (size_t i = 0; i < arraysize(kPreloadIDs); ++i) {
1270       if (kPreloadIDs[i] == prs_id) {
1271         is_copyable = true;
1272         break;
1273       }
1274     }
1275     gfx::ImageSkia image_skia;
1276     for (int pass = 0; pass < 2; ++pass) {
1277       // Two passes: In the first pass, we process only scale factor
1278       // 100% and in the second pass all other scale factors. We
1279       // process scale factor 100% first because the first image added
1280       // in image_skia.AddRepresentation() determines the DIP size for
1281       // all representations.
1282       for (ScaleFactorToFileMap::const_iterator s2f = it->second.begin();
1283            s2f != it->second.end(); ++s2f) {
1284         ui::ScaleFactor scale_factor = s2f->first;
1285         if ((pass == 0 && scale_factor != ui::SCALE_FACTOR_100P) ||
1286             (pass == 1 && scale_factor == ui::SCALE_FACTOR_100P)) {
1287           continue;
1288         }
1289         scoped_refptr<base::RefCountedMemory> raw_data(
1290             ReadFileData(s2f->second));
1291         if (!raw_data.get() || !raw_data->size()) {
1292           LOG(ERROR) << "Could not load theme image"
1293                      << " prs_id=" << prs_id
1294                      << " scale_factor_enum=" << scale_factor
1295                      << " file=" << s2f->second.value()
1296                      << (raw_data.get() ? " (zero size)" : " (read error)");
1297           return false;
1298         }
1299         if (is_copyable) {
1300           int raw_id = GetRawIDByPersistentID(prs_id, scale_factor);
1301           image_memory_[raw_id] = raw_data;
1302         } else {
1303           SkBitmap bitmap;
1304           if (gfx::PNGCodec::Decode(raw_data->front(), raw_data->size(),
1305                                     &bitmap)) {
1306             image_skia.AddRepresentation(
1307                 gfx::ImageSkiaRep(bitmap,
1308                                   ui::GetScaleForScaleFactor(scale_factor)));
1309           } else {
1310             NOTREACHED() << "Unable to decode theme image resource "
1311                          << it->first;
1312           }
1313         }
1314       }
1315     }
1316     if (!is_copyable && !image_skia.isNull())
1317       (*image_cache)[prs_id] = gfx::Image(image_skia);
1318   }
1319
1320   return true;
1321 }
1322
1323 void BrowserThemePack::CreateImages(ImageCache* images) const {
1324   CropImages(images);
1325   CreateFrameImages(images);
1326   CreateTintedButtons(GetTintInternal(ThemeProperties::TINT_BUTTONS), images);
1327   CreateTabBackgroundImages(images);
1328 }
1329
1330 void BrowserThemePack::CropImages(ImageCache* images) const {
1331   bool has_frame_border = HasFrameBorder();
1332   for (size_t i = 0; i < arraysize(kImagesToCrop); ++i) {
1333     if (has_frame_border && kImagesToCrop[i].skip_if_frame_border)
1334       continue;
1335
1336     int prs_id = kImagesToCrop[i].prs_id;
1337     ImageCache::iterator it = images->find(prs_id);
1338     if (it == images->end())
1339       continue;
1340
1341     int crop_height = kImagesToCrop[i].max_height;
1342     gfx::ImageSkia image_skia = it->second.AsImageSkia();
1343     (*images)[prs_id] = gfx::Image(gfx::ImageSkiaOperations::ExtractSubset(
1344         image_skia, gfx::Rect(0, 0, image_skia.width(), crop_height)));
1345   }
1346 }
1347
1348 void BrowserThemePack::CreateFrameImages(ImageCache* images) const {
1349   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
1350
1351   // Create all the output images in a separate cache and move them back into
1352   // the input images because there can be name collisions.
1353   ImageCache temp_output;
1354
1355   for (size_t i = 0; i < arraysize(kFrameTintMap); ++i) {
1356     int prs_id = kFrameTintMap[i].key;
1357     gfx::Image frame;
1358     // If there's no frame image provided for the specified id, then load
1359     // the default provided frame. If that's not provided, skip this whole
1360     // thing and just use the default images.
1361     int prs_base_id = 0;
1362
1363 #if defined(USE_ASH) && !defined(OS_CHROMEOS)
1364     if (prs_id == PRS_THEME_FRAME_INCOGNITO_INACTIVE_DESKTOP) {
1365       prs_base_id = images->count(PRS_THEME_FRAME_INCOGNITO_DESKTOP) ?
1366                     PRS_THEME_FRAME_INCOGNITO_DESKTOP : PRS_THEME_FRAME_DESKTOP;
1367     } else if (prs_id == PRS_THEME_FRAME_INACTIVE_DESKTOP) {
1368       prs_base_id = PRS_THEME_FRAME_DESKTOP;
1369     } else if (prs_id == PRS_THEME_FRAME_INCOGNITO_DESKTOP &&
1370                 !images->count(PRS_THEME_FRAME_INCOGNITO_DESKTOP)) {
1371       prs_base_id = PRS_THEME_FRAME_DESKTOP;
1372     }
1373 #endif
1374     if (!prs_base_id) {
1375       if (prs_id == PRS_THEME_FRAME_INCOGNITO_INACTIVE) {
1376         prs_base_id = images->count(PRS_THEME_FRAME_INCOGNITO) ?
1377                       PRS_THEME_FRAME_INCOGNITO : PRS_THEME_FRAME;
1378       } else if (prs_id == PRS_THEME_FRAME_OVERLAY_INACTIVE) {
1379         prs_base_id = PRS_THEME_FRAME_OVERLAY;
1380       } else if (prs_id == PRS_THEME_FRAME_INACTIVE) {
1381         prs_base_id = PRS_THEME_FRAME;
1382       } else if (prs_id == PRS_THEME_FRAME_INCOGNITO &&
1383                  !images->count(PRS_THEME_FRAME_INCOGNITO)) {
1384         prs_base_id = PRS_THEME_FRAME;
1385       } else {
1386         prs_base_id = prs_id;
1387       }
1388     }
1389     if (images->count(prs_id)) {
1390       frame = (*images)[prs_id];
1391     } else if (prs_base_id != prs_id && images->count(prs_base_id)) {
1392       frame = (*images)[prs_base_id];
1393     } else if (prs_base_id == PRS_THEME_FRAME_OVERLAY) {
1394 #if defined(USE_ASH) && !defined(OS_CHROMEOS)
1395       if (images->count(PRS_THEME_FRAME_DESKTOP)) {
1396 #else
1397       if (images->count(PRS_THEME_FRAME)) {
1398 #endif
1399         // If there is no theme overlay, don't tint the default frame,
1400         // because it will overwrite the custom frame image when we cache and
1401         // reload from disk.
1402         frame = gfx::Image();
1403       }
1404     } else {
1405       // If the theme doesn't specify an image, then apply the tint to
1406       // the default frame.
1407       frame = rb.GetImageNamed(IDR_THEME_FRAME);
1408 #if defined(USE_ASH) && !defined(OS_CHROMEOS)
1409       if (prs_id >= PRS_THEME_FRAME_DESKTOP &&
1410           prs_id <= PRS_THEME_FRAME_INCOGNITO_INACTIVE_DESKTOP) {
1411         frame = rb.GetImageNamed(IDR_THEME_FRAME_DESKTOP);
1412       }
1413 #endif
1414     }
1415     if (!frame.IsEmpty()) {
1416       temp_output[prs_id] = CreateHSLShiftedImage(
1417           frame, GetTintInternal(kFrameTintMap[i].value));
1418     }
1419   }
1420   MergeImageCaches(temp_output, images);
1421 }
1422
1423 void BrowserThemePack::CreateTintedButtons(
1424     const color_utils::HSL& button_tint,
1425     ImageCache* processed_images) const {
1426   if (button_tint.h != -1 || button_tint.s != -1 || button_tint.l != -1) {
1427     ResourceBundle& rb = ResourceBundle::GetSharedInstance();
1428     const std::set<int>& idr_ids =
1429         ThemeProperties::GetTintableToolbarButtons();
1430     for (std::set<int>::const_iterator it = idr_ids.begin();
1431          it != idr_ids.end(); ++it) {
1432       int prs_id = GetPersistentIDByIDR(*it);
1433       DCHECK(prs_id > 0);
1434
1435       // Fetch the image by IDR...
1436       gfx::Image& button = rb.GetImageNamed(*it);
1437
1438       // but save a version with the persistent ID.
1439       (*processed_images)[prs_id] =
1440           CreateHSLShiftedImage(button, button_tint);
1441     }
1442   }
1443 }
1444
1445 void BrowserThemePack::CreateTabBackgroundImages(ImageCache* images) const {
1446   ImageCache temp_output;
1447   for (size_t i = 0; i < arraysize(kTabBackgroundMap); ++i) {
1448     int prs_id = kTabBackgroundMap[i].key;
1449     int prs_base_id = kTabBackgroundMap[i].value;
1450
1451     // We only need to generate the background tab images if we were provided
1452     // with a PRS_THEME_FRAME.
1453     ImageCache::const_iterator it = images->find(prs_base_id);
1454     if (it != images->end()) {
1455       gfx::ImageSkia image_to_tint = (it->second).AsImageSkia();
1456       color_utils::HSL hsl_shift = GetTintInternal(
1457           ThemeProperties::TINT_BACKGROUND_TAB);
1458       int vertical_offset = images->count(prs_id)
1459                             ? kRestoredTabVerticalOffset : 0;
1460
1461       gfx::ImageSkia overlay;
1462       ImageCache::const_iterator overlay_it = images->find(prs_id);
1463       if (overlay_it != images->end())
1464         overlay = overlay_it->second.AsImageSkia();
1465
1466       gfx::ImageSkiaSource* source = new TabBackgroundImageSource(
1467           image_to_tint, overlay, hsl_shift, vertical_offset);
1468       // ImageSkia takes ownership of |source|.
1469       temp_output[prs_id] = gfx::Image(gfx::ImageSkia(source,
1470           image_to_tint.size()));
1471     }
1472   }
1473   MergeImageCaches(temp_output, images);
1474 }
1475
1476 void BrowserThemePack::RepackImages(const ImageCache& images,
1477                                     RawImages* reencoded_images) const {
1478   for (ImageCache::const_iterator it = images.begin();
1479        it != images.end(); ++it) {
1480     gfx::ImageSkia image_skia = *it->second.ToImageSkia();
1481
1482     typedef std::vector<gfx::ImageSkiaRep> ImageSkiaReps;
1483     ImageSkiaReps image_reps = image_skia.image_reps();
1484     if (image_reps.empty()) {
1485       NOTREACHED() << "No image reps for resource " << it->first << ".";
1486     }
1487     for (ImageSkiaReps::iterator rep_it = image_reps.begin();
1488          rep_it != image_reps.end(); ++rep_it) {
1489       std::vector<unsigned char> bitmap_data;
1490       if (!gfx::PNGCodec::EncodeBGRASkBitmap(rep_it->sk_bitmap(), false,
1491                                              &bitmap_data)) {
1492         NOTREACHED() << "Image file for resource " << it->first
1493                      << " could not be encoded.";
1494       }
1495       int raw_id = GetRawIDByPersistentID(
1496           it->first,
1497           ui::GetSupportedScaleFactor(rep_it->scale()));
1498       (*reencoded_images)[raw_id] =
1499           base::RefCountedBytes::TakeVector(&bitmap_data);
1500     }
1501   }
1502 }
1503
1504 void BrowserThemePack::MergeImageCaches(
1505     const ImageCache& source, ImageCache* destination) const {
1506   for (ImageCache::const_iterator it = source.begin(); it != source.end();
1507        ++it) {
1508     (*destination)[it->first] = it->second;
1509   }
1510 }
1511
1512 void BrowserThemePack::AddRawImagesTo(const RawImages& images,
1513                                       RawDataForWriting* out) const {
1514   for (RawImages::const_iterator it = images.begin(); it != images.end();
1515        ++it) {
1516     (*out)[it->first] = base::StringPiece(
1517         it->second->front_as<char>(), it->second->size());
1518   }
1519 }
1520
1521 color_utils::HSL BrowserThemePack::GetTintInternal(int id) const {
1522   if (tints_) {
1523     for (size_t i = 0; i < kTintTableLength; ++i) {
1524       if (tints_[i].id == id) {
1525         color_utils::HSL hsl;
1526         hsl.h = tints_[i].h;
1527         hsl.s = tints_[i].s;
1528         hsl.l = tints_[i].l;
1529         return hsl;
1530       }
1531     }
1532   }
1533
1534   return ThemeProperties::GetDefaultTint(id);
1535 }
1536
1537 int BrowserThemePack::GetRawIDByPersistentID(
1538     int prs_id,
1539     ui::ScaleFactor scale_factor) const {
1540   if (prs_id < 0)
1541     return -1;
1542
1543   for (size_t i = 0; i < scale_factors_.size(); ++i) {
1544     if (scale_factors_[i] == scale_factor)
1545       return ((GetMaxPersistentId() + 1) * i) + prs_id;
1546   }
1547   return -1;
1548 }
1549
1550 bool BrowserThemePack::GetScaleFactorFromManifestKey(
1551     const std::string& key,
1552     ui::ScaleFactor* scale_factor) const {
1553   int percent = 0;
1554   if (base::StringToInt(key, &percent)) {
1555     float scale = static_cast<float>(percent) / 100.0f;
1556     for (size_t i = 0; i < scale_factors_.size(); ++i) {
1557       if (fabs(ui::GetScaleForScaleFactor(scale_factors_[i]) - scale)
1558               < 0.001) {
1559         *scale_factor = scale_factors_[i];
1560         return true;
1561       }
1562     }
1563   }
1564   return false;
1565 }
1566
1567 void BrowserThemePack::GenerateRawImageForAllSupportedScales(int prs_id) {
1568   // Compute (by scaling) bitmaps for |prs_id| for any scale factors
1569   // for which the theme author did not provide a bitmap. We compute
1570   // the bitmaps using the highest scale factor that theme author
1571   // provided.
1572   // Note: We use only supported scale factors. For example, if scale
1573   // factor 2x is supported by the current system, but 1.8x is not and
1574   // if the theme author did not provide an image for 2x but one for
1575   // 1.8x, we will not use the 1.8x image here. Here we will only use
1576   // images provided for scale factors supported by the current system.
1577
1578   // See if any image is missing. If not, we're done.
1579   bool image_missing = false;
1580   for (size_t i = 0; i < scale_factors_.size(); ++i) {
1581     int raw_id = GetRawIDByPersistentID(prs_id, scale_factors_[i]);
1582     if (image_memory_.find(raw_id) == image_memory_.end()) {
1583       image_missing = true;
1584       break;
1585     }
1586   }
1587   if (!image_missing)
1588     return;
1589
1590   // Find available scale factor with highest scale.
1591   ui::ScaleFactor available_scale_factor = ui::SCALE_FACTOR_NONE;
1592   for (size_t i = 0; i < scale_factors_.size(); ++i) {
1593     int raw_id = GetRawIDByPersistentID(prs_id, scale_factors_[i]);
1594     if ((available_scale_factor == ui::SCALE_FACTOR_NONE ||
1595          (ui::GetScaleForScaleFactor(scale_factors_[i]) >
1596           ui::GetScaleForScaleFactor(available_scale_factor))) &&
1597         image_memory_.find(raw_id) != image_memory_.end()) {
1598       available_scale_factor = scale_factors_[i];
1599     }
1600   }
1601   // If no scale factor is available, we're done.
1602   if (available_scale_factor == ui::SCALE_FACTOR_NONE)
1603     return;
1604
1605   // Get bitmap for the available scale factor.
1606   int available_raw_id = GetRawIDByPersistentID(prs_id, available_scale_factor);
1607   RawImages::const_iterator it = image_memory_.find(available_raw_id);
1608   SkBitmap available_bitmap;
1609   if (!gfx::PNGCodec::Decode(it->second->front(),
1610                              it->second->size(),
1611                              &available_bitmap)) {
1612     NOTREACHED() << "Unable to decode theme image for prs_id="
1613                  << prs_id << " for scale_factor=" << available_scale_factor;
1614     return;
1615   }
1616
1617   // Fill in all missing scale factors by scaling the available bitmap.
1618   for (size_t i = 0; i < scale_factors_.size(); ++i) {
1619     int scaled_raw_id = GetRawIDByPersistentID(prs_id, scale_factors_[i]);
1620     if (image_memory_.find(scaled_raw_id) != image_memory_.end())
1621       continue;
1622     SkBitmap scaled_bitmap =
1623         CreateLowQualityResizedBitmap(available_bitmap,
1624                                       available_scale_factor,
1625                                       scale_factors_[i]);
1626     std::vector<unsigned char> bitmap_data;
1627     if (!gfx::PNGCodec::EncodeBGRASkBitmap(scaled_bitmap,
1628                                            false,
1629                                            &bitmap_data)) {
1630       NOTREACHED() << "Unable to encode theme image for prs_id="
1631                    << prs_id << " for scale_factor=" << scale_factors_[i];
1632       break;
1633     }
1634     image_memory_[scaled_raw_id] =
1635         base::RefCountedBytes::TakeVector(&bitmap_data);
1636   }
1637 }