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/memory/ref_counted_memory.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/stl_util.h"
  12 #include "base/strings/string_number_conversions.h"
  13 #include "base/strings/string_util.h"
  14 #include "base/strings/utf_string_conversions.h"
  15 #include "base/threading/sequenced_worker_pool.h"
  16 #include "base/threading/thread_restrictions.h"
  17 #include "base/values.h"
  18 #include "chrome/browser/themes/theme_properties.h"
  19 #include "chrome/common/extensions/manifest_handlers/theme_handler.h"
  20 #include "content/public/browser/browser_thread.h"
  21 #include "extensions/common/id_util.h"
  22 #include "grit/theme_resources.h"
  23 #include "grit/ui_resources.h"
  24 #include "net/base/file_stream.h"
  25 #include "net/base/net_errors.h"
  26 #include "third_party/skia/include/core/SkCanvas.h"
  27 #include "ui/base/resource/data_pack.h"
  28 #include "ui/base/resource/resource_bundle.h"
  29 #include "ui/gfx/canvas.h"
  30 #include "ui/gfx/codec/png_codec.h"
  31 #include "ui/gfx/image/canvas_image_source.h"
  32 #include "ui/gfx/image/image.h"
  33 #include "ui/gfx/image/image_skia.h"
  34 #include "ui/gfx/image/image_skia_operations.h"
  35 #include "ui/gfx/screen.h"
  36 #include "ui/gfx/size_conversions.h"
  37 #include "ui/gfx/skia_util.h"
  38
  39 using content::BrowserThread;
  40 using extensions::Extension;
  41
  42 namespace {
  43
  44 // Version number of the current theme pack. We just throw out and rebuild
  45 // theme packs that aren't int-equal to this. Increment this number if you
  46 // change default theme assets.
  47 const int kThemePackVersion = 32;
  48
  49 // IDs that are in the DataPack won't clash with the positive integer
  50 // uint16. kHeaderID should always have the maximum value because we want the
  51 // "header" to be written last. That way we can detect whether the pack was
  52 // successfully written and ignore and regenerate if it was only partially
  53 // written (i.e. chrome crashed on a different thread while writing the pack).
  54 const int kMaxID = 0x0000FFFF;  // Max unsigned 16-bit int.
  55 const int kHeaderID = kMaxID - 1;
  56 const int kTintsID = kMaxID - 2;
  57 const int kColorsID = kMaxID - 3;
  58 const int kDisplayPropertiesID = kMaxID - 4;
  59 const int kSourceImagesID = kMaxID - 5;
  60 const int kScaleFactorsID = kMaxID - 6;
  61
  62 // The sum of kFrameBorderThickness and kNonClientRestoredExtraThickness from
  63 // OpaqueBrowserFrameView.
  64 const int kRestoredTabVerticalOffset = 15;
  65
  66 // Persistent constants for the main images that we need. These have the same
  67 // names as their IDR_* counterparts but these values will always stay the
  68 // same.
  69 const int PRS_THEME_FRAME = 1;
  70 const int PRS_THEME_FRAME_INACTIVE = 2;
  71 const int PRS_THEME_FRAME_INCOGNITO = 3;
  72 const int PRS_THEME_FRAME_INCOGNITO_INACTIVE = 4;
  73 const int PRS_THEME_TOOLBAR = 5;
  74 const int PRS_THEME_TAB_BACKGROUND = 6;
  75 const int PRS_THEME_TAB_BACKGROUND_INCOGNITO = 7;
  76 const int PRS_THEME_TAB_BACKGROUND_V = 8;
  77 const int PRS_THEME_NTP_BACKGROUND = 9;
  78 const int PRS_THEME_FRAME_OVERLAY = 10;
  79 const int PRS_THEME_FRAME_OVERLAY_INACTIVE = 11;
  80 const int PRS_THEME_BUTTON_BACKGROUND = 12;
  81 const int PRS_THEME_NTP_ATTRIBUTION = 13;
  82 const int PRS_THEME_WINDOW_CONTROL_BACKGROUND = 14;
  83
  84 struct PersistingImagesTable {
  85   // A non-changing integer ID meant to be saved in theme packs. This ID must
  86   // not change between versions of chrome.
  87   int persistent_id;
  88
  89   // The IDR that depends on the whims of GRIT and therefore changes whenever
  90   // someone adds a new resource.
  91   int idr_id;
  92
  93   // String to check for when parsing theme manifests or NULL if this isn't
  94   // supposed to be changeable by the user.
  95   const char* key;
  96 };
  97
  98 // IDR_* resource names change whenever new resources are added; use persistent
  99 // IDs when storing to a cached pack.
 100 PersistingImagesTable kPersistingImages[] = {
 101   { PRS_THEME_FRAME, IDR_THEME_FRAME,
 102     "theme_frame" },
 103   { PRS_THEME_FRAME_INACTIVE, IDR_THEME_FRAME_INACTIVE,
 104     "theme_frame_inactive" },
 105   { PRS_THEME_FRAME_INCOGNITO, IDR_THEME_FRAME_INCOGNITO,
 106     "theme_frame_incognito" },
 107   { PRS_THEME_FRAME_INCOGNITO_INACTIVE, IDR_THEME_FRAME_INCOGNITO_INACTIVE,
 108     "theme_frame_incognito_inactive" },
 109   { PRS_THEME_TOOLBAR, IDR_THEME_TOOLBAR,
 110     "theme_toolbar" },
 111   { PRS_THEME_TAB_BACKGROUND, IDR_THEME_TAB_BACKGROUND,
 112     "theme_tab_background" },
 113   { PRS_THEME_TAB_BACKGROUND_INCOGNITO, IDR_THEME_TAB_BACKGROUND_INCOGNITO,
 114     "theme_tab_background_incognito" },
 115   { PRS_THEME_TAB_BACKGROUND_V, IDR_THEME_TAB_BACKGROUND_V,
 116     "theme_tab_background_v"},
 117   { PRS_THEME_NTP_BACKGROUND, IDR_THEME_NTP_BACKGROUND,
 118     "theme_ntp_background" },
 119   { PRS_THEME_FRAME_OVERLAY, IDR_THEME_FRAME_OVERLAY,
 120     "theme_frame_overlay" },
 121   { PRS_THEME_FRAME_OVERLAY_INACTIVE, IDR_THEME_FRAME_OVERLAY_INACTIVE,
 122     "theme_frame_overlay_inactive" },
 123   { PRS_THEME_BUTTON_BACKGROUND, IDR_THEME_BUTTON_BACKGROUND,
 124     "theme_button_background" },
 125   { PRS_THEME_NTP_ATTRIBUTION, IDR_THEME_NTP_ATTRIBUTION,
 126     "theme_ntp_attribution" },
 127   { PRS_THEME_WINDOW_CONTROL_BACKGROUND, IDR_THEME_WINDOW_CONTROL_BACKGROUND,
 128     "theme_window_control_background"},
 129
 130   // The rest of these entries have no key because they can't be overridden
 131   // from the json manifest.
 132   { 15, IDR_BACK, NULL },
 133   { 16, IDR_BACK_D, NULL },
 134   { 17, IDR_BACK_H, NULL },
 135   { 18, IDR_BACK_P, NULL },
 136   { 19, IDR_FORWARD, NULL },
 137   { 20, IDR_FORWARD_D, NULL },
 138   { 21, IDR_FORWARD_H, NULL },
 139   { 22, IDR_FORWARD_P, NULL },
 140   { 23, IDR_HOME, NULL },
 141   { 24, IDR_HOME_H, NULL },
 142   { 25, IDR_HOME_P, NULL },
 143   { 26, IDR_RELOAD, NULL },
 144   { 27, IDR_RELOAD_H, NULL },
 145   { 28, IDR_RELOAD_P, NULL },
 146   { 29, IDR_STOP, NULL },
 147   { 30, IDR_STOP_D, NULL },
 148   { 31, IDR_STOP_H, NULL },
 149   { 32, IDR_STOP_P, NULL },
 150   { 33, IDR_BROWSER_ACTIONS_OVERFLOW, NULL },
 151   { 34, IDR_BROWSER_ACTIONS_OVERFLOW_H, NULL },
 152   { 35, IDR_BROWSER_ACTIONS_OVERFLOW_P, NULL },
 153   { 36, IDR_TOOLS, NULL },
 154   { 37, IDR_TOOLS_H, NULL },
 155   { 38, IDR_TOOLS_P, NULL },
 156   { 39, IDR_MENU_DROPARROW, NULL },
 157   { 40, IDR_THROBBER, NULL },
 158   { 41, IDR_THROBBER_WAITING, NULL },
 159   { 42, IDR_THROBBER_LIGHT, NULL },
 160   { 43, IDR_TOOLBAR_BEZEL_HOVER, NULL },
 161   { 44, IDR_TOOLBAR_BEZEL_PRESSED, NULL },
 162   { 45, IDR_TOOLS_BAR, NULL },
 163 };
 164 const size_t kPersistingImagesLength = arraysize(kPersistingImages);
 165
 166 #if defined(OS_WIN) && defined(USE_AURA)
 167 // Persistent theme ids for Windows AURA.
 168 const int PRS_THEME_FRAME_WIN = 100;
 169 const int PRS_THEME_FRAME_INACTIVE_WIN = 101;
 170 const int PRS_THEME_FRAME_INCOGNITO_WIN = 102;
 171 const int PRS_THEME_FRAME_INCOGNITO_INACTIVE_WIN = 103;
 172 const int PRS_THEME_TOOLBAR_WIN = 104;
 173 const int PRS_THEME_TAB_BACKGROUND_WIN = 105;
 174 const int PRS_THEME_TAB_BACKGROUND_INCOGNITO_WIN = 106;
 175
 176 // Persistent theme to resource id mapping for Windows AURA.
 177 PersistingImagesTable kPersistingImagesWinDesktopAura[] = {
 178   { PRS_THEME_FRAME_WIN, IDR_THEME_FRAME_WIN,
 179     "theme_frame" },
 180   { PRS_THEME_FRAME_INACTIVE_WIN, IDR_THEME_FRAME_INACTIVE_WIN,
 181     "theme_frame_inactive" },
 182   { PRS_THEME_FRAME_INCOGNITO_WIN, IDR_THEME_FRAME_INCOGNITO_WIN,
 183     "theme_frame_incognito" },
 184   { PRS_THEME_FRAME_INCOGNITO_INACTIVE_WIN,
 185     IDR_THEME_FRAME_INCOGNITO_INACTIVE_WIN,
 186     "theme_frame_incognito_inactive" },
 187   { PRS_THEME_TOOLBAR_WIN, IDR_THEME_TOOLBAR_WIN,
 188     "theme_toolbar" },
 189   { PRS_THEME_TAB_BACKGROUND_WIN, IDR_THEME_TAB_BACKGROUND_WIN,
 190     "theme_tab_background" },
 191   { PRS_THEME_TAB_BACKGROUND_INCOGNITO_WIN,
 192     IDR_THEME_TAB_BACKGROUND_INCOGNITO_WIN,
 193     "theme_tab_background_incognito" },
 194 };
 195 const size_t kPersistingImagesWinDesktopAuraLength =
 196     arraysize(kPersistingImagesWinDesktopAura);
 197 #endif
 198
 199 int GetPersistentIDByNameHelper(const std::string& key,
 200                                 const PersistingImagesTable* image_table,
 201                                 size_t image_table_size) {
 202   for (size_t i = 0; i < image_table_size; ++i) {
 203     if (image_table[i].key != NULL &&
 204         base::strcasecmp(key.c_str(), image_table[i].key) == 0) {
 205       return image_table[i].persistent_id;
 206     }
 207   }
 208   return -1;
 209 }
 210
 211 int GetPersistentIDByName(const std::string& key) {
 212   return GetPersistentIDByNameHelper(key,
 213                                      kPersistingImages,
 214                                      kPersistingImagesLength);
 215 }
 216
 217 int GetPersistentIDByIDR(int idr) {
 218   static std::map<int,int>* lookup_table = new std::map<int,int>();
 219   if (lookup_table->empty()) {
 220     for (size_t i = 0; i < kPersistingImagesLength; ++i) {
 221       int idr = kPersistingImages[i].idr_id;
 222       int prs_id = kPersistingImages[i].persistent_id;
 223       (*lookup_table)[idr] = prs_id;
 224     }
 225 #if defined(OS_WIN) && defined(USE_AURA)
 226     for (size_t i = 0; i < kPersistingImagesWinDesktopAuraLength; ++i) {
 227       int idr = kPersistingImagesWinDesktopAura[i].idr_id;
 228       int prs_id = kPersistingImagesWinDesktopAura[i].persistent_id;
 229       (*lookup_table)[idr] = prs_id;
 230     }
 231 #endif
 232   }
 233   std::map<int,int>::iterator it = lookup_table->find(idr);
 234   return (it == lookup_table->end()) ? -1 : it->second;
 235 }
 236
 237 // Returns true if the scales in |input| match those in |expected|.
 238 // The order must match as the index is used in determining the raw id.
 239 bool InputScalesValid(const base::StringPiece& input,
 240                       const std::vector<ui::ScaleFactor>& expected) {
 241   size_t scales_size = static_cast<size_t>(input.size() / sizeof(float));
 242   if (scales_size != expected.size())
 243     return false;
 244   scoped_ptr<float[]> scales(new float[scales_size]);
 245   // Do a memcpy to avoid misaligned memory access.
 246   memcpy(scales.get(), input.data(), input.size());
 247   for (size_t index = 0; index < scales_size; ++index) {
 248     if (scales[index] != ui::GetImageScale(expected[index]))
 249       return false;
 250   }
 251   return true;
 252 }
 253
 254 // Returns |scale_factors| as a string to be written to disk.
 255 std::string GetScaleFactorsAsString(
 256     const std::vector<ui::ScaleFactor>& scale_factors) {
 257   scoped_ptr<float[]> scales(new float[scale_factors.size()]);
 258   for (size_t i = 0; i < scale_factors.size(); ++i)
 259     scales[i] = ui::GetImageScale(scale_factors[i]);
 260   std::string out_string = std::string(
 261       reinterpret_cast<const char*>(scales.get()),
 262       scale_factors.size() * sizeof(float));
 263   return out_string;
 264 }
 265
 266 struct StringToIntTable {
 267   const char* key;
 268   ThemeProperties::OverwritableByUserThemeProperty id;
 269 };
 270
 271 // Strings used by themes to identify tints in the JSON.
 272 StringToIntTable kTintTable[] = {
 273   { "buttons", ThemeProperties::TINT_BUTTONS },
 274   { "frame", ThemeProperties::TINT_FRAME },
 275   { "frame_inactive", ThemeProperties::TINT_FRAME_INACTIVE },
 276   { "frame_incognito", ThemeProperties::TINT_FRAME_INCOGNITO },
 277   { "frame_incognito_inactive",
 278     ThemeProperties::TINT_FRAME_INCOGNITO_INACTIVE },
 279   { "background_tab", ThemeProperties::TINT_BACKGROUND_TAB },
 280 };
 281 const size_t kTintTableLength = arraysize(kTintTable);
 282
 283 // Strings used by themes to identify colors in the JSON.
 284 StringToIntTable kColorTable[] = {
 285   { "frame", ThemeProperties::COLOR_FRAME },
 286   { "frame_inactive", ThemeProperties::COLOR_FRAME_INACTIVE },
 287   { "frame_incognito", ThemeProperties::COLOR_FRAME_INCOGNITO },
 288   { "frame_incognito_inactive",
 289     ThemeProperties::COLOR_FRAME_INCOGNITO_INACTIVE },
 290   { "toolbar", ThemeProperties::COLOR_TOOLBAR },
 291   { "tab_text", ThemeProperties::COLOR_TAB_TEXT },
 292   { "tab_background_text", ThemeProperties::COLOR_BACKGROUND_TAB_TEXT },
 293   { "bookmark_text", ThemeProperties::COLOR_BOOKMARK_TEXT },
 294   { "ntp_background", ThemeProperties::COLOR_NTP_BACKGROUND },
 295   { "ntp_text", ThemeProperties::COLOR_NTP_TEXT },
 296   { "ntp_link", ThemeProperties::COLOR_NTP_LINK },
 297   { "ntp_link_underline", ThemeProperties::COLOR_NTP_LINK_UNDERLINE },
 298   { "ntp_header", ThemeProperties::COLOR_NTP_HEADER },
 299   { "ntp_section", ThemeProperties::COLOR_NTP_SECTION },
 300   { "ntp_section_text", ThemeProperties::COLOR_NTP_SECTION_TEXT },
 301   { "ntp_section_link", ThemeProperties::COLOR_NTP_SECTION_LINK },
 302   { "ntp_section_link_underline",
 303     ThemeProperties::COLOR_NTP_SECTION_LINK_UNDERLINE },
 304   { "button_background", ThemeProperties::COLOR_BUTTON_BACKGROUND },
 305 };
 306 const size_t kColorTableLength = arraysize(kColorTable);
 307
 308 // Strings used by themes to identify display properties keys in JSON.
 309 StringToIntTable kDisplayProperties[] = {
 310   { "ntp_background_alignment",
 311     ThemeProperties::NTP_BACKGROUND_ALIGNMENT },
 312   { "ntp_background_repeat", ThemeProperties::NTP_BACKGROUND_TILING },
 313   { "ntp_logo_alternate", ThemeProperties::NTP_LOGO_ALTERNATE },
 314 };
 315 const size_t kDisplayPropertiesSize = arraysize(kDisplayProperties);
 316
 317 int GetIntForString(const std::string& key,
 318                     StringToIntTable* table,
 319                     size_t table_length) {
 320   for (size_t i = 0; i < table_length; ++i) {
 321     if (base::strcasecmp(key.c_str(), table[i].key) == 0) {
 322       return table[i].id;
 323     }
 324   }
 325
 326   return -1;
 327 }
 328
 329 struct IntToIntTable {
 330   int key;
 331   int value;
 332 };
 333
 334 // Mapping used in CreateFrameImages() to associate frame images with the
 335 // tint ID that should maybe be applied to it.
 336 IntToIntTable kFrameTintMap[] = {
 337   { PRS_THEME_FRAME, ThemeProperties::TINT_FRAME },
 338   { PRS_THEME_FRAME_INACTIVE, ThemeProperties::TINT_FRAME_INACTIVE },
 339   { PRS_THEME_FRAME_OVERLAY, ThemeProperties::TINT_FRAME },
 340   { PRS_THEME_FRAME_OVERLAY_INACTIVE,
 341     ThemeProperties::TINT_FRAME_INACTIVE },
 342   { PRS_THEME_FRAME_INCOGNITO, ThemeProperties::TINT_FRAME_INCOGNITO },
 343   { PRS_THEME_FRAME_INCOGNITO_INACTIVE,
 344     ThemeProperties::TINT_FRAME_INCOGNITO_INACTIVE },
 345 #if defined(OS_WIN) && defined(USE_AURA)
 346   { PRS_THEME_FRAME_WIN, ThemeProperties::TINT_FRAME },
 347   { PRS_THEME_FRAME_INACTIVE_WIN, ThemeProperties::TINT_FRAME_INACTIVE },
 348   { PRS_THEME_FRAME_INCOGNITO_WIN, ThemeProperties::TINT_FRAME_INCOGNITO },
 349   { PRS_THEME_FRAME_INCOGNITO_INACTIVE_WIN,
 350     ThemeProperties::TINT_FRAME_INCOGNITO_INACTIVE },
 351 #endif
 352 };
 353
 354 // Mapping used in GenerateTabBackgroundImages() to associate what frame image
 355 // goes with which tab background.
 356 IntToIntTable kTabBackgroundMap[] = {
 357   { PRS_THEME_TAB_BACKGROUND, PRS_THEME_FRAME },
 358   { PRS_THEME_TAB_BACKGROUND_INCOGNITO, PRS_THEME_FRAME_INCOGNITO },
 359 #if defined(OS_WIN) && defined(USE_AURA)
 360   { PRS_THEME_TAB_BACKGROUND_WIN, PRS_THEME_FRAME_WIN },
 361   { PRS_THEME_TAB_BACKGROUND_INCOGNITO_WIN, PRS_THEME_FRAME_INCOGNITO_WIN },
 362 #endif
 363 };
 364
 365 struct CropEntry {
 366   int prs_id;
 367
 368   // The maximum useful height of the image at |prs_id|.
 369   int max_height;
 370
 371   // Whether cropping the image at |prs_id| should be skipped on OSes which
 372   // have a frame border to the left and right of the web contents.
 373   // This should be true for images which can be used to decorate the border to
 374   // the left and the right of the web contents.
 375   bool skip_if_frame_border;
 376 };
 377
 378 // The images which should be cropped before being saved to the data pack. The
 379 // maximum heights are meant to be conservative as to give room for the UI to
 380 // change without the maximum heights having to be modified.
 381 // |kThemePackVersion| must be incremented if any of the maximum heights below
 382 // are modified.
 383 struct CropEntry kImagesToCrop[] = {
 384   { PRS_THEME_FRAME, 120, true },
 385   { PRS_THEME_FRAME_INACTIVE, 120, true },
 386   { PRS_THEME_FRAME_INCOGNITO, 120, true },
 387   { PRS_THEME_FRAME_INCOGNITO_INACTIVE, 120, true },
 388   { PRS_THEME_FRAME_OVERLAY, 120, true },
 389   { PRS_THEME_FRAME_OVERLAY_INACTIVE, 120, true },
 390   { PRS_THEME_TOOLBAR, 200, false },
 391   { PRS_THEME_BUTTON_BACKGROUND, 60, false },
 392   { PRS_THEME_WINDOW_CONTROL_BACKGROUND, 50, false },
 393 #if defined(OS_WIN) && defined(USE_AURA)
 394   { PRS_THEME_TOOLBAR_WIN, 200, false }
 395 #endif
 396 };
 397
 398
 399 // A list of images that don't need tinting or any other modification and can
 400 // be byte-copied directly into the finished DataPack. This should contain the
 401 // persistent IDs for all themeable image IDs that aren't in kFrameTintMap,
 402 // kTabBackgroundMap or kImagesToCrop.
 403 const int kPreloadIDs[] = {
 404   PRS_THEME_NTP_BACKGROUND,
 405   PRS_THEME_NTP_ATTRIBUTION,
 406 };
 407
 408 // Returns true if this OS uses a browser frame which has a non zero width to
 409 // the left and the right of the web contents.
 410 bool HasFrameBorder() {
 411 #if defined(OS_CHROMEOS) || defined(OS_MACOSX)
 412   return false;
 413 #else
 414   return true;
 415 #endif
 416 }
 417
 418 // Returns a piece of memory with the contents of the file |path|.
 419 base::RefCountedMemory* ReadFileData(const base::FilePath& path) {
 420   if (!path.empty()) {
 421     net::FileStream file(NULL);
 422     int flags = base::PLATFORM_FILE_OPEN | base::PLATFORM_FILE_READ;
 423     if (file.OpenSync(path, flags) == net::OK) {
 424       int64 avail = file.Available();
 425       if (avail > 0 && avail < INT_MAX) {
 426         size_t size = static_cast<size_t>(avail);
 427         std::vector<unsigned char> raw_data;
 428         raw_data.resize(size);
 429         char* data = reinterpret_cast<char*>(&(raw_data.front()));
 430         if (file.ReadUntilComplete(data, size) == avail)
 431           return base::RefCountedBytes::TakeVector(&raw_data);
 432       }
 433     }
 434   }
 435
 436   return NULL;
 437 }
 438
 439 // Shifts an image's HSL values. The caller is responsible for deleting
 440 // the returned image.
 441 gfx::Image CreateHSLShiftedImage(const gfx::Image& image,
 442                                  const color_utils::HSL& hsl_shift) {
 443   const gfx::ImageSkia* src_image = image.ToImageSkia();
 444   return gfx::Image(gfx::ImageSkiaOperations::CreateHSLShiftedImage(
 445       *src_image, hsl_shift));
 446 }
 447
 448 // Computes a bitmap at one scale from a bitmap at a different scale.
 449 SkBitmap CreateLowQualityResizedBitmap(const SkBitmap& source_bitmap,
 450                                        ui::ScaleFactor source_scale_factor,
 451                                        ui::ScaleFactor desired_scale_factor) {
 452   gfx::Size scaled_size = gfx::ToCeiledSize(
 453       gfx::ScaleSize(gfx::Size(source_bitmap.width(),
 454                                source_bitmap.height()),
 455                      ui::GetImageScale(desired_scale_factor) /
 456                      ui::GetImageScale(source_scale_factor)));
 457   SkBitmap scaled_bitmap;
 458   scaled_bitmap.setConfig(SkBitmap::kARGB_8888_Config,
 459                           scaled_size.width(),
 460                           scaled_size.height());
 461   if (!scaled_bitmap.allocPixels())
 462     SK_CRASH();
 463   scaled_bitmap.eraseARGB(0, 0, 0, 0);
 464   SkCanvas canvas(scaled_bitmap);
 465   SkRect scaled_bounds = RectToSkRect(gfx::Rect(scaled_size));
 466   // Note(oshima): The following scaling code doesn't work with
 467   // a mask image.
 468   canvas.drawBitmapRect(source_bitmap, NULL, scaled_bounds);
 469   return scaled_bitmap;
 470 }
 471
 472 // A ImageSkiaSource that scales 100P image to the target scale factor
 473 // if the ImageSkiaRep for the target scale factor isn't available.
 474 class ThemeImageSource: public gfx::ImageSkiaSource {
 475  public:
 476   explicit ThemeImageSource(const gfx::ImageSkia& source) : source_(source) {
 477   }
 478   virtual ~ThemeImageSource() {}
 479
 480   virtual gfx::ImageSkiaRep GetImageForScale(float scale) OVERRIDE {
 481     if (source_.HasRepresentation(scale))
 482       return source_.GetRepresentation(scale);
 483     const gfx::ImageSkiaRep& rep_100p = source_.GetRepresentation(1.0f);
 484     SkBitmap scaled_bitmap = CreateLowQualityResizedBitmap(
 485         rep_100p.sk_bitmap(),
 486         ui::SCALE_FACTOR_100P,
 487         ui::GetSupportedScaleFactor(scale));
 488     return gfx::ImageSkiaRep(scaled_bitmap, scale);
 489   }
 490
 491  private:
 492   const gfx::ImageSkia source_;
 493
 494   DISALLOW_COPY_AND_ASSIGN(ThemeImageSource);
 495 };
 496
 497 // An ImageSkiaSource that delays decoding PNG data into bitmaps until
 498 // needed. Missing data for a scale factor is computed by scaling data for an
 499 // available scale factor. Computed bitmaps are stored for future look up.
 500 class ThemeImagePngSource : public gfx::ImageSkiaSource {
 501  public:
 502   typedef std::map<ui::ScaleFactor,
 503                    scoped_refptr<base::RefCountedMemory> > PngMap;
 504
 505   explicit ThemeImagePngSource(const PngMap& png_map) : png_map_(png_map) {}
 506
 507   virtual ~ThemeImagePngSource() {}
 508
 509  private:
 510   virtual gfx::ImageSkiaRep GetImageForScale(float scale) OVERRIDE {
 511     ui::ScaleFactor scale_factor = ui::GetSupportedScaleFactor(scale);
 512     // Look up the bitmap for |scale factor| in the bitmap map. If found
 513     // return it.
 514     BitmapMap::const_iterator exact_bitmap_it = bitmap_map_.find(scale_factor);
 515     if (exact_bitmap_it != bitmap_map_.end())
 516       return gfx::ImageSkiaRep(exact_bitmap_it->second, scale);
 517
 518     // Look up the raw PNG data for |scale_factor| in the png map. If found,
 519     // decode it, store the result in the bitmap map and return it.
 520     PngMap::const_iterator exact_png_it = png_map_.find(scale_factor);
 521     if (exact_png_it != png_map_.end()) {
 522       SkBitmap bitmap;
 523       if (!gfx::PNGCodec::Decode(exact_png_it->second->front(),
 524                                  exact_png_it->second->size(),
 525                                  &bitmap)) {
 526         NOTREACHED();
 527         return gfx::ImageSkiaRep();
 528       }
 529       bitmap_map_[scale_factor] = bitmap;
 530       return gfx::ImageSkiaRep(bitmap, scale);
 531     }
 532
 533     // Find an available PNG for another scale factor. We want to use the
 534     // highest available scale factor.
 535     PngMap::const_iterator available_png_it = png_map_.end();
 536     for (PngMap::const_iterator png_it = png_map_.begin();
 537          png_it != png_map_.end(); ++png_it) {
 538       if (available_png_it == png_map_.end() ||
 539           ui::GetImageScale(png_it->first) >
 540           ui::GetImageScale(available_png_it->first)) {
 541         available_png_it = png_it;
 542       }
 543     }
 544     if (available_png_it == png_map_.end())
 545       return gfx::ImageSkiaRep();
 546     ui::ScaleFactor available_scale_factor = available_png_it->first;
 547
 548     // Look up the bitmap for |available_scale_factor| in the bitmap map.
 549     // If not found, decode the corresponging png data, store the result
 550     // in the bitmap map.
 551     BitmapMap::const_iterator available_bitmap_it =
 552         bitmap_map_.find(available_scale_factor);
 553     if (available_bitmap_it == bitmap_map_.end()) {
 554       SkBitmap available_bitmap;
 555       if (!gfx::PNGCodec::Decode(available_png_it->second->front(),
 556                                  available_png_it->second->size(),
 557                                  &available_bitmap)) {
 558         NOTREACHED();
 559         return gfx::ImageSkiaRep();
 560       }
 561       bitmap_map_[available_scale_factor] = available_bitmap;
 562       available_bitmap_it = bitmap_map_.find(available_scale_factor);
 563     }
 564
 565     // Scale the available bitmap to the desired scale factor, store the result
 566     // in the bitmap map and return it.
 567     SkBitmap scaled_bitmap = CreateLowQualityResizedBitmap(
 568         available_bitmap_it->second,
 569         available_scale_factor,
 570         scale_factor);
 571     bitmap_map_[scale_factor] = scaled_bitmap;
 572     return gfx::ImageSkiaRep(scaled_bitmap, scale);
 573   }
 574
 575   PngMap png_map_;
 576
 577   typedef std::map<ui::ScaleFactor, SkBitmap> BitmapMap;
 578   BitmapMap bitmap_map_;
 579
 580   DISALLOW_COPY_AND_ASSIGN(ThemeImagePngSource);
 581 };
 582
 583 class TabBackgroundImageSource: public gfx::CanvasImageSource {
 584  public:
 585   TabBackgroundImageSource(const gfx::ImageSkia& image_to_tint,
 586                            const gfx::ImageSkia& overlay,
 587                            const color_utils::HSL& hsl_shift,
 588                            int vertical_offset)
 589       : gfx::CanvasImageSource(image_to_tint.size(), false),
 590         image_to_tint_(image_to_tint),
 591         overlay_(overlay),
 592         hsl_shift_(hsl_shift),
 593         vertical_offset_(vertical_offset) {
 594   }
 595
 596   virtual ~TabBackgroundImageSource() {
 597   }
 598
 599   // Overridden from CanvasImageSource:
 600   virtual void Draw(gfx::Canvas* canvas) OVERRIDE {
 601     gfx::ImageSkia bg_tint =
 602         gfx::ImageSkiaOperations::CreateHSLShiftedImage(image_to_tint_,
 603             hsl_shift_);
 604     canvas->TileImageInt(bg_tint, 0, vertical_offset_, 0, 0,
 605         size().width(), size().height());
 606
 607     // If they've provided a custom image, overlay it.
 608     if (!overlay_.isNull()) {
 609       canvas->TileImageInt(overlay_, 0, 0, size().width(),
 610                            overlay_.height());
 611     }
 612   }
 613
 614  private:
 615   const gfx::ImageSkia image_to_tint_;
 616   const gfx::ImageSkia overlay_;
 617   const color_utils::HSL hsl_shift_;
 618   const int vertical_offset_;
 619
 620   DISALLOW_COPY_AND_ASSIGN(TabBackgroundImageSource);
 621 };
 622
 623 }  // namespace
 624
 625 BrowserThemePack::~BrowserThemePack() {
 626   if (!data_pack_.get()) {
 627     delete header_;
 628     delete [] tints_;
 629     delete [] colors_;
 630     delete [] display_properties_;
 631     delete [] source_images_;
 632   }
 633 }
 634
 635 // static
 636 scoped_refptr<BrowserThemePack> BrowserThemePack::BuildFromExtension(
 637     const Extension* extension) {
 638   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 639   DCHECK(extension);
 640   DCHECK(extension->is_theme());
 641
 642   scoped_refptr<BrowserThemePack> pack(new BrowserThemePack);
 643   pack->BuildHeader(extension);
 644   pack->BuildTintsFromJSON(extensions::ThemeInfo::GetTints(extension));
 645   pack->BuildColorsFromJSON(extensions::ThemeInfo::GetColors(extension));
 646   pack->BuildDisplayPropertiesFromJSON(
 647       extensions::ThemeInfo::GetDisplayProperties(extension));
 648
 649   // Builds the images. (Image building is dependent on tints).
 650   FilePathMap file_paths;
 651   pack->ParseImageNamesFromJSON(
 652       extensions::ThemeInfo::GetImages(extension),
 653       extension->path(),
 654       &file_paths);
 655   pack->BuildSourceImagesArray(file_paths);
 656
 657   if (!pack->LoadRawBitmapsTo(file_paths, &pack->images_on_ui_thread_))
 658     return NULL;
 659
 660   pack->CreateImages(&pack->images_on_ui_thread_);
 661
 662   // Make sure the |images_on_file_thread_| has bitmaps for supported
 663   // scale factors before passing to FILE thread.
 664   pack->images_on_file_thread_ = pack->images_on_ui_thread_;
 665   for (ImageCache::iterator it = pack->images_on_file_thread_.begin();
 666        it != pack->images_on_file_thread_.end(); ++it) {
 667     gfx::ImageSkia* image_skia =
 668         const_cast<gfx::ImageSkia*>(it->second.ToImageSkia());
 669     image_skia->MakeThreadSafe();
 670   }
 671
 672   // Set ThemeImageSource on |images_on_ui_thread_| to resample the source
 673   // image if a caller of BrowserThemePack::GetImageNamed() requests an
 674   // ImageSkiaRep for a scale factor not specified by the theme author.
 675   // Callers of BrowserThemePack::GetImageNamed() to be able to retrieve
 676   // ImageSkiaReps for all supported scale factors.
 677   for (ImageCache::iterator it = pack->images_on_ui_thread_.begin();
 678        it != pack->images_on_ui_thread_.end(); ++it) {
 679     const gfx::ImageSkia source_image_skia = it->second.AsImageSkia();
 680     ThemeImageSource* source = new ThemeImageSource(source_image_skia);
 681     // image_skia takes ownership of source.
 682     gfx::ImageSkia image_skia(source, source_image_skia.size());
 683     it->second = gfx::Image(image_skia);
 684   }
 685
 686   // Generate raw images (for new-tab-page attribution and background) for
 687   // any missing scale from an available scale image.
 688   for (size_t i = 0; i < arraysize(kPreloadIDs); ++i) {
 689     pack->GenerateRawImageForAllSupportedScales(kPreloadIDs[i]);
 690   }
 691
 692   // The BrowserThemePack is now in a consistent state.
 693   return pack;
 694 }
 695
 696 // static
 697 scoped_refptr<BrowserThemePack> BrowserThemePack::BuildFromDataPack(
 698     const base::FilePath& path, const std::string& expected_id) {
 699   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 700   // Allow IO on UI thread due to deep-seated theme design issues.
 701   // (see http://crbug.com/80206)
 702   base::ThreadRestrictions::ScopedAllowIO allow_io;
 703   scoped_refptr<BrowserThemePack> pack(new BrowserThemePack);
 704   // Scale factor parameter is moot as data pack has image resources for all
 705   // supported scale factors.
 706   pack->data_pack_.reset(
 707       new ui::DataPack(ui::SCALE_FACTOR_NONE));
 708
 709   if (!pack->data_pack_->LoadFromPath(path)) {
 710     LOG(ERROR) << "Failed to load theme data pack.";
 711     return NULL;
 712   }
 713
 714   base::StringPiece pointer;
 715   if (!pack->data_pack_->GetStringPiece(kHeaderID, &pointer))
 716     return NULL;
 717   pack->header_ = reinterpret_cast<BrowserThemePackHeader*>(const_cast<char*>(
 718       pointer.data()));
 719
 720   if (pack->header_->version != kThemePackVersion) {
 721     DLOG(ERROR) << "BuildFromDataPack failure! Version mismatch!";
 722     return NULL;
 723   }
 724   // TODO(erg): Check endianess once DataPack works on the other endian.
 725   std::string theme_id(reinterpret_cast<char*>(pack->header_->theme_id),
 726                        extensions::id_util::kIdSize);
 727   std::string truncated_id =
 728       expected_id.substr(0, extensions::id_util::kIdSize);
 729   if (theme_id != truncated_id) {
 730     DLOG(ERROR) << "Wrong id: " << theme_id << " vs " << expected_id;
 731     return NULL;
 732   }
 733
 734   if (!pack->data_pack_->GetStringPiece(kTintsID, &pointer))
 735     return NULL;
 736   pack->tints_ = reinterpret_cast<TintEntry*>(const_cast<char*>(
 737       pointer.data()));
 738
 739   if (!pack->data_pack_->GetStringPiece(kColorsID, &pointer))
 740     return NULL;
 741   pack->colors_ =
 742       reinterpret_cast<ColorPair*>(const_cast<char*>(pointer.data()));
 743
 744   if (!pack->data_pack_->GetStringPiece(kDisplayPropertiesID, &pointer))
 745     return NULL;
 746   pack->display_properties_ = reinterpret_cast<DisplayPropertyPair*>(
 747       const_cast<char*>(pointer.data()));
 748
 749   if (!pack->data_pack_->GetStringPiece(kSourceImagesID, &pointer))
 750     return NULL;
 751   pack->source_images_ = reinterpret_cast<int*>(
 752       const_cast<char*>(pointer.data()));
 753
 754   if (!pack->data_pack_->GetStringPiece(kScaleFactorsID, &pointer))
 755     return NULL;
 756
 757   if (!InputScalesValid(pointer, pack->scale_factors_)) {
 758     DLOG(ERROR) << "BuildFromDataPack failure! The pack scale factors differ "
 759                 << "from those supported by platform.";
 760   }
 761   return pack;
 762 }
 763
 764 // static
 765 void BrowserThemePack::GetThemeableImageIDRs(std::set<int>* result) {
 766   if (!result)
 767     return;
 768
 769   result->clear();
 770   for (size_t i = 0; i < kPersistingImagesLength; ++i)
 771     result->insert(kPersistingImages[i].idr_id);
 772
 773 #if defined(OS_WIN) && defined(USE_AURA)
 774   for (size_t i = 0; i < kPersistingImagesWinDesktopAuraLength; ++i)
 775     result->insert(kPersistingImagesWinDesktopAura[i].idr_id);
 776 #endif
 777 }
 778
 779 bool BrowserThemePack::WriteToDisk(const base::FilePath& path) const {
 780   // Add resources for each of the property arrays.
 781   RawDataForWriting resources;
 782   resources[kHeaderID] = base::StringPiece(
 783       reinterpret_cast<const char*>(header_), sizeof(BrowserThemePackHeader));
 784   resources[kTintsID] = base::StringPiece(
 785       reinterpret_cast<const char*>(tints_),
 786       sizeof(TintEntry[kTintTableLength]));
 787   resources[kColorsID] = base::StringPiece(
 788       reinterpret_cast<const char*>(colors_),
 789       sizeof(ColorPair[kColorTableLength]));
 790   resources[kDisplayPropertiesID] = base::StringPiece(
 791       reinterpret_cast<const char*>(display_properties_),
 792       sizeof(DisplayPropertyPair[kDisplayPropertiesSize]));
 793
 794   int source_count = 1;
 795   int* end = source_images_;
 796   for (; *end != -1 ; end++)
 797     source_count++;
 798   resources[kSourceImagesID] = base::StringPiece(
 799       reinterpret_cast<const char*>(source_images_),
 800       source_count * sizeof(*source_images_));
 801
 802   // Store results of GetScaleFactorsAsString() in std::string as
 803   // base::StringPiece does not copy data in constructor.
 804   std::string scale_factors_string = GetScaleFactorsAsString(scale_factors_);
 805   resources[kScaleFactorsID] = scale_factors_string;
 806
 807   AddRawImagesTo(image_memory_, &resources);
 808
 809   RawImages reencoded_images;
 810   RepackImages(images_on_file_thread_, &reencoded_images);
 811   AddRawImagesTo(reencoded_images, &resources);
 812
 813   return ui::DataPack::WritePack(path, resources, ui::DataPack::BINARY);
 814 }
 815
 816 bool BrowserThemePack::GetTint(int id, color_utils::HSL* hsl) const {
 817   if (tints_) {
 818     for (size_t i = 0; i < kTintTableLength; ++i) {
 819       if (tints_[i].id == id) {
 820         hsl->h = tints_[i].h;
 821         hsl->s = tints_[i].s;
 822         hsl->l = tints_[i].l;
 823         return true;
 824       }
 825     }
 826   }
 827
 828   return false;
 829 }
 830
 831 bool BrowserThemePack::GetColor(int id, SkColor* color) const {
 832   if (colors_) {
 833     for (size_t i = 0; i < kColorTableLength; ++i) {
 834       if (colors_[i].id == id) {
 835         *color = colors_[i].color;
 836         return true;
 837       }
 838     }
 839   }
 840
 841   return false;
 842 }
 843
 844 bool BrowserThemePack::GetDisplayProperty(int id, int* result) const {
 845   if (display_properties_) {
 846     for (size_t i = 0; i < kDisplayPropertiesSize; ++i) {
 847       if (display_properties_[i].id == id) {
 848         *result = display_properties_[i].property;
 849         return true;
 850       }
 851     }
 852   }
 853
 854   return false;
 855 }
 856
 857 gfx::Image BrowserThemePack::GetImageNamed(int idr_id) {
 858   int prs_id = GetPersistentIDByIDR(idr_id);
 859   if (prs_id == -1)
 860     return gfx::Image();
 861
 862   // Check if the image is cached.
 863   ImageCache::const_iterator image_iter = images_on_ui_thread_.find(prs_id);
 864   if (image_iter != images_on_ui_thread_.end())
 865     return image_iter->second;
 866
 867   ThemeImagePngSource::PngMap png_map;
 868   for (size_t i = 0; i < scale_factors_.size(); ++i) {
 869     scoped_refptr<base::RefCountedMemory> memory =
 870         GetRawData(idr_id, scale_factors_[i]);
 871     if (memory.get())
 872       png_map[scale_factors_[i]] = memory;
 873   }
 874   if (!png_map.empty()) {
 875     gfx::ImageSkia image_skia(new ThemeImagePngSource(png_map),
 876                               ui::SCALE_FACTOR_100P);
 877     // |image_skia| takes ownership of ThemeImagePngSource.
 878     gfx::Image ret = gfx::Image(image_skia);
 879     images_on_ui_thread_[prs_id] = ret;
 880     return ret;
 881   }
 882
 883   return gfx::Image();
 884 }
 885
 886 base::RefCountedMemory* BrowserThemePack::GetRawData(
 887     int idr_id,
 888     ui::ScaleFactor scale_factor) const {
 889   base::RefCountedMemory* memory = NULL;
 890   int prs_id = GetPersistentIDByIDR(idr_id);
 891   int raw_id = GetRawIDByPersistentID(prs_id, scale_factor);
 892
 893   if (raw_id != -1) {
 894     if (data_pack_.get()) {
 895       memory = data_pack_->GetStaticMemory(raw_id);
 896     } else {
 897       RawImages::const_iterator it = image_memory_.find(raw_id);
 898       if (it != image_memory_.end()) {
 899         memory = it->second.get();
 900       }
 901     }
 902   }
 903
 904   return memory;
 905 }
 906
 907 bool BrowserThemePack::HasCustomImage(int idr_id) const {
 908   int prs_id = GetPersistentIDByIDR(idr_id);
 909   if (prs_id == -1)
 910     return false;
 911
 912   int* img = source_images_;
 913   for (; *img != -1; ++img) {
 914     if (*img == prs_id)
 915       return true;
 916   }
 917
 918   return false;
 919 }
 920
 921 // private:
 922
 923 BrowserThemePack::BrowserThemePack()
 924     : CustomThemeSupplier(EXTENSION),
 925       header_(NULL),
 926       tints_(NULL),
 927       colors_(NULL),
 928       display_properties_(NULL),
 929       source_images_(NULL) {
 930   scale_factors_ = ui::GetSupportedScaleFactors();
 931 }
 932
 933 void BrowserThemePack::BuildHeader(const Extension* extension) {
 934   header_ = new BrowserThemePackHeader;
 935   header_->version = kThemePackVersion;
 936
 937   // TODO(erg): Need to make this endian safe on other computers. Prerequisite
 938   // is that ui::DataPack removes this same check.
 939 #if defined(__BYTE_ORDER)
 940   // Linux check
 941   COMPILE_ASSERT(__BYTE_ORDER == __LITTLE_ENDIAN,
 942                  datapack_assumes_little_endian);
 943 #elif defined(__BIG_ENDIAN__)
 944   // Mac check
 945   #error DataPack assumes little endian
 946 #endif
 947   header_->little_endian = 1;
 948
 949   const std::string& id = extension->id();
 950   memcpy(header_->theme_id, id.c_str(), extensions::id_util::kIdSize);
 951 }
 952
 953 void BrowserThemePack::BuildTintsFromJSON(
 954     const base::DictionaryValue* tints_value) {
 955   tints_ = new TintEntry[kTintTableLength];
 956   for (size_t i = 0; i < kTintTableLength; ++i) {
 957     tints_[i].id = -1;
 958     tints_[i].h = -1;
 959     tints_[i].s = -1;
 960     tints_[i].l = -1;
 961   }
 962
 963   if (!tints_value)
 964     return;
 965
 966   // Parse the incoming data from |tints_value| into an intermediary structure.
 967   std::map<int, color_utils::HSL> temp_tints;
 968   for (base::DictionaryValue::Iterator iter(*tints_value); !iter.IsAtEnd();
 969        iter.Advance()) {
 970     const base::ListValue* tint_list;
 971     if (iter.value().GetAsList(&tint_list) &&
 972         (tint_list->GetSize() == 3)) {
 973       color_utils::HSL hsl = { -1, -1, -1 };
 974
 975       if (tint_list->GetDouble(0, &hsl.h) &&
 976           tint_list->GetDouble(1, &hsl.s) &&
 977           tint_list->GetDouble(2, &hsl.l)) {
 978         int id = GetIntForString(iter.key(), kTintTable, kTintTableLength);
 979         if (id != -1) {
 980           temp_tints[id] = hsl;
 981         }
 982       }
 983     }
 984   }
 985
 986   // Copy data from the intermediary data structure to the array.
 987   size_t count = 0;
 988   for (std::map<int, color_utils::HSL>::const_iterator it =
 989            temp_tints.begin();
 990        it != temp_tints.end() && count < kTintTableLength;
 991        ++it, ++count) {
 992     tints_[count].id = it->first;
 993     tints_[count].h = it->second.h;
 994     tints_[count].s = it->second.s;
 995     tints_[count].l = it->second.l;
 996   }
 997 }
 998
 999 void BrowserThemePack::BuildColorsFromJSON(
1000     const base::DictionaryValue* colors_value) {
1001   colors_ = new ColorPair[kColorTableLength];
1002   for (size_t i = 0; i < kColorTableLength; ++i) {
1003     colors_[i].id = -1;
1004     colors_[i].color = SkColorSetRGB(0, 0, 0);
1005   }
1006
1007   std::map<int, SkColor> temp_colors;
1008   if (colors_value)
1009     ReadColorsFromJSON(colors_value, &temp_colors);
1010   GenerateMissingColors(&temp_colors);
1011
1012   // Copy data from the intermediary data structure to the array.
1013   size_t count = 0;
1014   for (std::map<int, SkColor>::const_iterator it = temp_colors.begin();
1015        it != temp_colors.end() && count < kColorTableLength; ++it, ++count) {
1016     colors_[count].id = it->first;
1017     colors_[count].color = it->second;
1018   }
1019 }
1020
1021 void BrowserThemePack::ReadColorsFromJSON(
1022     const base::DictionaryValue* colors_value,
1023     std::map<int, SkColor>* temp_colors) {
1024   // Parse the incoming data from |colors_value| into an intermediary structure.
1025   for (base::DictionaryValue::Iterator iter(*colors_value); !iter.IsAtEnd();
1026        iter.Advance()) {
1027     const base::ListValue* color_list;
1028     if (iter.value().GetAsList(&color_list) &&
1029         ((color_list->GetSize() == 3) || (color_list->GetSize() == 4))) {
1030       SkColor color = SK_ColorWHITE;
1031       int r, g, b;
1032       if (color_list->GetInteger(0, &r) &&
1033           color_list->GetInteger(1, &g) &&
1034           color_list->GetInteger(2, &b)) {
1035         if (color_list->GetSize() == 4) {
1036           double alpha;
1037           int alpha_int;
1038           if (color_list->GetDouble(3, &alpha)) {
1039             color = SkColorSetARGB(static_cast<int>(alpha * 255), r, g, b);
1040           } else if (color_list->GetInteger(3, &alpha_int) &&
1041                      (alpha_int == 0 || alpha_int == 1)) {
1042             color = SkColorSetARGB(alpha_int ? 255 : 0, r, g, b);
1043           } else {
1044             // Invalid entry for part 4.
1045             continue;
1046           }
1047         } else {
1048           color = SkColorSetRGB(r, g, b);
1049         }
1050
1051         int id = GetIntForString(iter.key(), kColorTable, kColorTableLength);
1052         if (id != -1) {
1053           (*temp_colors)[id] = color;
1054         }
1055       }
1056     }
1057   }
1058 }
1059
1060 void BrowserThemePack::GenerateMissingColors(
1061     std::map<int, SkColor>* colors) {
1062   // Generate link colors, if missing. (See GetColor()).
1063   if (!colors->count(ThemeProperties::COLOR_NTP_HEADER) &&
1064       colors->count(ThemeProperties::COLOR_NTP_SECTION)) {
1065     (*colors)[ThemeProperties::COLOR_NTP_HEADER] =
1066         (*colors)[ThemeProperties::COLOR_NTP_SECTION];
1067   }
1068
1069   if (!colors->count(ThemeProperties::COLOR_NTP_SECTION_LINK_UNDERLINE) &&
1070       colors->count(ThemeProperties::COLOR_NTP_SECTION_LINK)) {
1071     SkColor color_section_link =
1072         (*colors)[ThemeProperties::COLOR_NTP_SECTION_LINK];
1073     (*colors)[ThemeProperties::COLOR_NTP_SECTION_LINK_UNDERLINE] =
1074         SkColorSetA(color_section_link, SkColorGetA(color_section_link) / 3);
1075   }
1076
1077   if (!colors->count(ThemeProperties::COLOR_NTP_LINK_UNDERLINE) &&
1078       colors->count(ThemeProperties::COLOR_NTP_LINK)) {
1079     SkColor color_link = (*colors)[ThemeProperties::COLOR_NTP_LINK];
1080     (*colors)[ThemeProperties::COLOR_NTP_LINK_UNDERLINE] =
1081         SkColorSetA(color_link, SkColorGetA(color_link) / 3);
1082   }
1083
1084   // Generate frame colors, if missing. (See GenerateFrameColors()).
1085   SkColor frame;
1086   std::map<int, SkColor>::const_iterator it =
1087       colors->find(ThemeProperties::COLOR_FRAME);
1088   if (it != colors->end()) {
1089     frame = it->second;
1090   } else {
1091     frame = ThemeProperties::GetDefaultColor(
1092         ThemeProperties::COLOR_FRAME);
1093   }
1094
1095   if (!colors->count(ThemeProperties::COLOR_FRAME)) {
1096     (*colors)[ThemeProperties::COLOR_FRAME] =
1097         HSLShift(frame, GetTintInternal(ThemeProperties::TINT_FRAME));
1098   }
1099   if (!colors->count(ThemeProperties::COLOR_FRAME_INACTIVE)) {
1100     (*colors)[ThemeProperties::COLOR_FRAME_INACTIVE] =
1101         HSLShift(frame, GetTintInternal(
1102             ThemeProperties::TINT_FRAME_INACTIVE));
1103   }
1104   if (!colors->count(ThemeProperties::COLOR_FRAME_INCOGNITO)) {
1105     (*colors)[ThemeProperties::COLOR_FRAME_INCOGNITO] =
1106         HSLShift(frame, GetTintInternal(
1107             ThemeProperties::TINT_FRAME_INCOGNITO));
1108   }
1109   if (!colors->count(ThemeProperties::COLOR_FRAME_INCOGNITO_INACTIVE)) {
1110     (*colors)[ThemeProperties::COLOR_FRAME_INCOGNITO_INACTIVE] =
1111         HSLShift(frame, GetTintInternal(
1112             ThemeProperties::TINT_FRAME_INCOGNITO_INACTIVE));
1113   }
1114 }
1115
1116 void BrowserThemePack::BuildDisplayPropertiesFromJSON(
1117     const base::DictionaryValue* display_properties_value) {
1118   display_properties_ = new DisplayPropertyPair[kDisplayPropertiesSize];
1119   for (size_t i = 0; i < kDisplayPropertiesSize; ++i) {
1120     display_properties_[i].id = -1;
1121     display_properties_[i].property = 0;
1122   }
1123
1124   if (!display_properties_value)
1125     return;
1126
1127   std::map<int, int> temp_properties;
1128   for (base::DictionaryValue::Iterator iter(*display_properties_value);
1129        !iter.IsAtEnd(); iter.Advance()) {
1130     int property_id = GetIntForString(iter.key(), kDisplayProperties,
1131                                       kDisplayPropertiesSize);
1132     switch (property_id) {
1133       case ThemeProperties::NTP_BACKGROUND_ALIGNMENT: {
1134         std::string val;
1135         if (iter.value().GetAsString(&val)) {
1136           temp_properties[ThemeProperties::NTP_BACKGROUND_ALIGNMENT] =
1137               ThemeProperties::StringToAlignment(val);
1138         }
1139         break;
1140       }
1141       case ThemeProperties::NTP_BACKGROUND_TILING: {
1142         std::string val;
1143         if (iter.value().GetAsString(&val)) {
1144           temp_properties[ThemeProperties::NTP_BACKGROUND_TILING] =
1145               ThemeProperties::StringToTiling(val);
1146         }
1147         break;
1148       }
1149       case ThemeProperties::NTP_LOGO_ALTERNATE: {
1150         int val = 0;
1151         if (iter.value().GetAsInteger(&val))
1152           temp_properties[ThemeProperties::NTP_LOGO_ALTERNATE] = val;
1153         break;
1154       }
1155     }
1156   }
1157
1158   // Copy data from the intermediary data structure to the array.
1159   size_t count = 0;
1160   for (std::map<int, int>::const_iterator it = temp_properties.begin();
1161        it != temp_properties.end() && count < kDisplayPropertiesSize;
1162        ++it, ++count) {
1163     display_properties_[count].id = it->first;
1164     display_properties_[count].property = it->second;
1165   }
1166 }
1167
1168 void BrowserThemePack::ParseImageNamesFromJSON(
1169     const base::DictionaryValue* images_value,
1170     const base::FilePath& images_path,
1171     FilePathMap* file_paths) const {
1172   if (!images_value)
1173     return;
1174
1175   for (base::DictionaryValue::Iterator iter(*images_value); !iter.IsAtEnd();
1176        iter.Advance()) {
1177     if (iter.value().IsType(base::Value::TYPE_DICTIONARY)) {
1178       const base::DictionaryValue* inner_value = NULL;
1179       if (iter.value().GetAsDictionary(&inner_value)) {
1180         for (base::DictionaryValue::Iterator inner_iter(*inner_value);
1181              !inner_iter.IsAtEnd();
1182              inner_iter.Advance()) {
1183           std::string name;
1184           ui::ScaleFactor scale_factor = ui::SCALE_FACTOR_NONE;
1185           if (GetScaleFactorFromManifestKey(inner_iter.key(), &scale_factor) &&
1186               inner_iter.value().IsType(base::Value::TYPE_STRING) &&
1187               inner_iter.value().GetAsString(&name)) {
1188             AddFileAtScaleToMap(iter.key(),
1189                                 scale_factor,
1190                                 images_path.AppendASCII(name),
1191                                 file_paths);
1192           }
1193         }
1194       }
1195     } else if (iter.value().IsType(base::Value::TYPE_STRING)) {
1196       std::string name;
1197       if (iter.value().GetAsString(&name)) {
1198         AddFileAtScaleToMap(iter.key(),
1199                             ui::SCALE_FACTOR_100P,
1200                             images_path.AppendASCII(name),
1201                             file_paths);
1202       }
1203     }
1204   }
1205 }
1206
1207 void BrowserThemePack::AddFileAtScaleToMap(const std::string& image_name,
1208                                            ui::ScaleFactor scale_factor,
1209                                            const base::FilePath& image_path,
1210                                            FilePathMap* file_paths) const {
1211   int id = GetPersistentIDByName(image_name);
1212   if (id != -1)
1213     (*file_paths)[id][scale_factor] = image_path;
1214 #if defined(OS_WIN) && defined(USE_AURA)
1215   id = GetPersistentIDByNameHelper(image_name,
1216                                    kPersistingImagesWinDesktopAura,
1217                                    kPersistingImagesWinDesktopAuraLength);
1218   if (id != -1)
1219     (*file_paths)[id][scale_factor] = image_path;
1220 #endif
1221 }
1222
1223 void BrowserThemePack::BuildSourceImagesArray(const FilePathMap& file_paths) {
1224   std::vector<int> ids;
1225   for (FilePathMap::const_iterator it = file_paths.begin();
1226        it != file_paths.end(); ++it) {
1227     ids.push_back(it->first);
1228   }
1229
1230   source_images_ = new int[ids.size() + 1];
1231   std::copy(ids.begin(), ids.end(), source_images_);
1232   source_images_[ids.size()] = -1;
1233 }
1234
1235 bool BrowserThemePack::LoadRawBitmapsTo(
1236     const FilePathMap& file_paths,
1237     ImageCache* image_cache) {
1238   // Themes should be loaded on the file thread, not the UI thread.
1239   // http://crbug.com/61838
1240   base::ThreadRestrictions::ScopedAllowIO allow_io;
1241
1242   for (FilePathMap::const_iterator it = file_paths.begin();
1243        it != file_paths.end(); ++it) {
1244     int prs_id = it->first;
1245     // Some images need to go directly into |image_memory_|. No modification is
1246     // necessary or desirable.
1247     bool is_copyable = false;
1248     for (size_t i = 0; i < arraysize(kPreloadIDs); ++i) {
1249       if (kPreloadIDs[i] == prs_id) {
1250         is_copyable = true;
1251         break;
1252       }
1253     }
1254     gfx::ImageSkia image_skia;
1255     for (int pass = 0; pass < 2; ++pass) {
1256       // Two passes: In the first pass, we process only scale factor
1257       // 100% and in the second pass all other scale factors. We
1258       // process scale factor 100% first because the first image added
1259       // in image_skia.AddRepresentation() determines the DIP size for
1260       // all representations.
1261       for (ScaleFactorToFileMap::const_iterator s2f = it->second.begin();
1262            s2f != it->second.end(); ++s2f) {
1263         ui::ScaleFactor scale_factor = s2f->first;
1264         if ((pass == 0 && scale_factor != ui::SCALE_FACTOR_100P) ||
1265             (pass == 1 && scale_factor == ui::SCALE_FACTOR_100P)) {
1266           continue;
1267         }
1268         scoped_refptr<base::RefCountedMemory> raw_data(
1269             ReadFileData(s2f->second));
1270         if (!raw_data.get() || !raw_data->size()) {
1271           LOG(ERROR) << "Could not load theme image"
1272                      << " prs_id=" << prs_id
1273                      << " scale_factor_enum=" << scale_factor
1274                      << " file=" << s2f->second.value()
1275                      << (raw_data.get() ? " (zero size)" : " (read error)");
1276           return false;
1277         }
1278         if (is_copyable) {
1279           int raw_id = GetRawIDByPersistentID(prs_id, scale_factor);
1280           image_memory_[raw_id] = raw_data;
1281         } else {
1282           SkBitmap bitmap;
1283           if (gfx::PNGCodec::Decode(raw_data->front(), raw_data->size(),
1284                                     &bitmap)) {
1285             image_skia.AddRepresentation(
1286                 gfx::ImageSkiaRep(bitmap,
1287                                   ui::GetImageScale(scale_factor)));
1288           } else {
1289             NOTREACHED() << "Unable to decode theme image resource "
1290                          << it->first;
1291           }
1292         }
1293       }
1294     }
1295     if (!is_copyable && !image_skia.isNull())
1296       (*image_cache)[prs_id] = gfx::Image(image_skia);
1297   }
1298
1299   return true;
1300 }
1301
1302 void BrowserThemePack::CreateImages(ImageCache* images) const {
1303   CropImages(images);
1304   CreateFrameImages(images);
1305   CreateTintedButtons(GetTintInternal(ThemeProperties::TINT_BUTTONS), images);
1306   CreateTabBackgroundImages(images);
1307 }
1308
1309 void BrowserThemePack::CropImages(ImageCache* images) const {
1310   bool has_frame_border = HasFrameBorder();
1311   for (size_t i = 0; i < arraysize(kImagesToCrop); ++i) {
1312     if (has_frame_border && kImagesToCrop[i].skip_if_frame_border)
1313       continue;
1314
1315     int prs_id = kImagesToCrop[i].prs_id;
1316     ImageCache::iterator it = images->find(prs_id);
1317     if (it == images->end())
1318       continue;
1319
1320     int crop_height = kImagesToCrop[i].max_height;
1321     gfx::ImageSkia image_skia = it->second.AsImageSkia();
1322     (*images)[prs_id] = gfx::Image(gfx::ImageSkiaOperations::ExtractSubset(
1323         image_skia, gfx::Rect(0, 0, image_skia.width(), crop_height)));
1324   }
1325 }
1326
1327 void BrowserThemePack::CreateFrameImages(ImageCache* images) const {
1328   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
1329
1330   // Create all the output images in a separate cache and move them back into
1331   // the input images because there can be name collisions.
1332   ImageCache temp_output;
1333
1334   for (size_t i = 0; i < arraysize(kFrameTintMap); ++i) {
1335     int prs_id = kFrameTintMap[i].key;
1336     gfx::Image frame;
1337     // If there's no frame image provided for the specified id, then load
1338     // the default provided frame. If that's not provided, skip this whole
1339     // thing and just use the default images.
1340     int prs_base_id = 0;
1341
1342 #if defined(OS_WIN) && defined(USE_AURA)
1343     if (prs_id == PRS_THEME_FRAME_INCOGNITO_INACTIVE_WIN) {
1344       prs_base_id = images->count(PRS_THEME_FRAME_INCOGNITO_WIN) ?
1345                     PRS_THEME_FRAME_INCOGNITO_WIN : PRS_THEME_FRAME_WIN;
1346     } else if (prs_id == PRS_THEME_FRAME_INACTIVE_WIN) {
1347       prs_base_id = PRS_THEME_FRAME_WIN;
1348     } else if (prs_id == PRS_THEME_FRAME_INCOGNITO_WIN &&
1349                 !images->count(PRS_THEME_FRAME_INCOGNITO_WIN)) {
1350       prs_base_id = PRS_THEME_FRAME_WIN;
1351     }
1352 #endif
1353     if (!prs_base_id) {
1354       if (prs_id == PRS_THEME_FRAME_INCOGNITO_INACTIVE) {
1355         prs_base_id = images->count(PRS_THEME_FRAME_INCOGNITO) ?
1356                       PRS_THEME_FRAME_INCOGNITO : PRS_THEME_FRAME;
1357       } else if (prs_id == PRS_THEME_FRAME_OVERLAY_INACTIVE) {
1358         prs_base_id = PRS_THEME_FRAME_OVERLAY;
1359       } else if (prs_id == PRS_THEME_FRAME_INACTIVE) {
1360         prs_base_id = PRS_THEME_FRAME;
1361       } else if (prs_id == PRS_THEME_FRAME_INCOGNITO &&
1362                  !images->count(PRS_THEME_FRAME_INCOGNITO)) {
1363         prs_base_id = PRS_THEME_FRAME;
1364       } else {
1365         prs_base_id = prs_id;
1366       }
1367     }
1368     if (images->count(prs_id)) {
1369       frame = (*images)[prs_id];
1370     } else if (prs_base_id != prs_id && images->count(prs_base_id)) {
1371       frame = (*images)[prs_base_id];
1372     } else if (prs_base_id == PRS_THEME_FRAME_OVERLAY) {
1373 #if defined(OS_WIN) && defined(USE_AURA)
1374       if (images->count(PRS_THEME_FRAME_WIN)) {
1375 #else
1376       if (images->count(PRS_THEME_FRAME)) {
1377 #endif
1378         // If there is no theme overlay, don't tint the default frame,
1379         // because it will overwrite the custom frame image when we cache and
1380         // reload from disk.
1381         frame = gfx::Image();
1382       }
1383     } else {
1384       // If the theme doesn't specify an image, then apply the tint to
1385       // the default frame.
1386       frame = rb.GetImageNamed(IDR_THEME_FRAME);
1387 #if defined(OS_WIN) && defined(USE_AURA)
1388       if (prs_id >= PRS_THEME_FRAME_WIN &&
1389           prs_id <= PRS_THEME_FRAME_INCOGNITO_INACTIVE_WIN) {
1390         frame = rb.GetImageNamed(IDR_THEME_FRAME_WIN);
1391       }
1392 #endif
1393     }
1394     if (!frame.IsEmpty()) {
1395       temp_output[prs_id] = CreateHSLShiftedImage(
1396           frame, GetTintInternal(kFrameTintMap[i].value));
1397     }
1398   }
1399   MergeImageCaches(temp_output, images);
1400 }
1401
1402 void BrowserThemePack::CreateTintedButtons(
1403     const color_utils::HSL& button_tint,
1404     ImageCache* processed_images) const {
1405   if (button_tint.h != -1 || button_tint.s != -1 || button_tint.l != -1) {
1406     ResourceBundle& rb = ResourceBundle::GetSharedInstance();
1407     const std::set<int>& idr_ids =
1408         ThemeProperties::GetTintableToolbarButtons();
1409     for (std::set<int>::const_iterator it = idr_ids.begin();
1410          it != idr_ids.end(); ++it) {
1411       int prs_id = GetPersistentIDByIDR(*it);
1412       DCHECK(prs_id > 0);
1413
1414       // Fetch the image by IDR...
1415       gfx::Image& button = rb.GetImageNamed(*it);
1416
1417       // but save a version with the persistent ID.
1418       (*processed_images)[prs_id] =
1419           CreateHSLShiftedImage(button, button_tint);
1420     }
1421   }
1422 }
1423
1424 void BrowserThemePack::CreateTabBackgroundImages(ImageCache* images) const {
1425   ImageCache temp_output;
1426   for (size_t i = 0; i < arraysize(kTabBackgroundMap); ++i) {
1427     int prs_id = kTabBackgroundMap[i].key;
1428     int prs_base_id = kTabBackgroundMap[i].value;
1429
1430     // We only need to generate the background tab images if we were provided
1431     // with a PRS_THEME_FRAME.
1432     ImageCache::const_iterator it = images->find(prs_base_id);
1433     if (it != images->end()) {
1434       gfx::ImageSkia image_to_tint = (it->second).AsImageSkia();
1435       color_utils::HSL hsl_shift = GetTintInternal(
1436           ThemeProperties::TINT_BACKGROUND_TAB);
1437       int vertical_offset = images->count(prs_id)
1438                             ? kRestoredTabVerticalOffset : 0;
1439
1440       gfx::ImageSkia overlay;
1441       ImageCache::const_iterator overlay_it = images->find(prs_id);
1442       if (overlay_it != images->end())
1443         overlay = overlay_it->second.AsImageSkia();
1444
1445       gfx::ImageSkiaSource* source = new TabBackgroundImageSource(
1446           image_to_tint, overlay, hsl_shift, vertical_offset);
1447       // ImageSkia takes ownership of |source|.
1448       temp_output[prs_id] = gfx::Image(gfx::ImageSkia(source,
1449           image_to_tint.size()));
1450     }
1451   }
1452   MergeImageCaches(temp_output, images);
1453 }
1454
1455 void BrowserThemePack::RepackImages(const ImageCache& images,
1456                                     RawImages* reencoded_images) const {
1457   typedef std::vector<ui::ScaleFactor> ScaleFactors;
1458   for (ImageCache::const_iterator it = images.begin();
1459        it != images.end(); ++it) {
1460     gfx::ImageSkia image_skia = *it->second.ToImageSkia();
1461
1462     typedef std::vector<gfx::ImageSkiaRep> ImageSkiaReps;
1463     ImageSkiaReps image_reps = image_skia.image_reps();
1464     if (image_reps.empty()) {
1465       NOTREACHED() << "No image reps for resource " << it->first << ".";
1466     }
1467     for (ImageSkiaReps::iterator rep_it = image_reps.begin();
1468          rep_it != image_reps.end(); ++rep_it) {
1469       std::vector<unsigned char> bitmap_data;
1470       if (!gfx::PNGCodec::EncodeBGRASkBitmap(rep_it->sk_bitmap(), false,
1471                                              &bitmap_data)) {
1472         NOTREACHED() << "Image file for resource " << it->first
1473                      << " could not be encoded.";
1474       }
1475       int raw_id = GetRawIDByPersistentID(
1476           it->first,
1477           ui::GetSupportedScaleFactor(rep_it->scale()));
1478       (*reencoded_images)[raw_id] =
1479           base::RefCountedBytes::TakeVector(&bitmap_data);
1480     }
1481   }
1482 }
1483
1484 void BrowserThemePack::MergeImageCaches(
1485     const ImageCache& source, ImageCache* destination) const {
1486   for (ImageCache::const_iterator it = source.begin(); it != source.end();
1487        ++it) {
1488     (*destination)[it->first] = it->second;
1489   }
1490 }
1491
1492 void BrowserThemePack::AddRawImagesTo(const RawImages& images,
1493                                       RawDataForWriting* out) const {
1494   for (RawImages::const_iterator it = images.begin(); it != images.end();
1495        ++it) {
1496     (*out)[it->first] = base::StringPiece(
1497         reinterpret_cast<const char*>(it->second->front()), it->second->size());
1498   }
1499 }
1500
1501 color_utils::HSL BrowserThemePack::GetTintInternal(int id) const {
1502   if (tints_) {
1503     for (size_t i = 0; i < kTintTableLength; ++i) {
1504       if (tints_[i].id == id) {
1505         color_utils::HSL hsl;
1506         hsl.h = tints_[i].h;
1507         hsl.s = tints_[i].s;
1508         hsl.l = tints_[i].l;
1509         return hsl;
1510       }
1511     }
1512   }
1513
1514   return ThemeProperties::GetDefaultTint(id);
1515 }
1516
1517 int BrowserThemePack::GetRawIDByPersistentID(
1518     int prs_id,
1519     ui::ScaleFactor scale_factor) const {
1520   if (prs_id < 0)
1521     return -1;
1522
1523   for (size_t i = 0; i < scale_factors_.size(); ++i) {
1524     if (scale_factors_[i] == scale_factor)
1525       return static_cast<int>(kPersistingImagesLength * i) + prs_id;
1526   }
1527   return -1;
1528 }
1529
1530 bool BrowserThemePack::GetScaleFactorFromManifestKey(
1531     const std::string& key,
1532     ui::ScaleFactor* scale_factor) const {
1533   int percent = 0;
1534   if (base::StringToInt(key, &percent)) {
1535     float scale = static_cast<float>(percent) / 100.0f;
1536     for (size_t i = 0; i < scale_factors_.size(); ++i) {
1537       if (fabs(ui::GetImageScale(scale_factors_[i]) - scale) < 0.001) {
1538         *scale_factor = scale_factors_[i];
1539         return true;
1540       }
1541     }
1542   }
1543   return false;
1544 }
1545
1546 void BrowserThemePack::GenerateRawImageForAllSupportedScales(int prs_id) {
1547   // Compute (by scaling) bitmaps for |prs_id| for any scale factors
1548   // for which the theme author did not provide a bitmap. We compute
1549   // the bitmaps using the highest scale factor that theme author
1550   // provided.
1551   // Note: We use only supported scale factors. For example, if scale
1552   // factor 2x is supported by the current system, but 1.8x is not and
1553   // if the theme author did not provide an image for 2x but one for
1554   // 1.8x, we will not use the 1.8x image here. Here we will only use
1555   // images provided for scale factors supported by the current system.
1556
1557   // See if any image is missing. If not, we're done.
1558   bool image_missing = false;
1559   for (size_t i = 0; i < scale_factors_.size(); ++i) {
1560     int raw_id = GetRawIDByPersistentID(prs_id, scale_factors_[i]);
1561     if (image_memory_.find(raw_id) == image_memory_.end()) {
1562       image_missing = true;
1563       break;
1564     }
1565   }
1566   if (!image_missing)
1567     return;
1568
1569   // Find available scale factor with highest scale.
1570   ui::ScaleFactor available_scale_factor = ui::SCALE_FACTOR_NONE;
1571   for (size_t i = 0; i < scale_factors_.size(); ++i) {
1572     int raw_id = GetRawIDByPersistentID(prs_id, scale_factors_[i]);
1573     if ((available_scale_factor == ui::SCALE_FACTOR_NONE ||
1574          (ui::GetImageScale(scale_factors_[i]) >
1575           ui::GetImageScale(available_scale_factor))) &&
1576         image_memory_.find(raw_id) != image_memory_.end()) {
1577       available_scale_factor = scale_factors_[i];
1578     }
1579   }
1580   // If no scale factor is available, we're done.
1581   if (available_scale_factor == ui::SCALE_FACTOR_NONE)
1582     return;
1583
1584   // Get bitmap for the available scale factor.
1585   int available_raw_id = GetRawIDByPersistentID(prs_id, available_scale_factor);
1586   RawImages::const_iterator it = image_memory_.find(available_raw_id);
1587   SkBitmap available_bitmap;
1588   if (!gfx::PNGCodec::Decode(it->second->front(),
1589                              it->second->size(),
1590                              &available_bitmap)) {
1591     NOTREACHED() << "Unable to decode theme image for prs_id="
1592                  << prs_id << " for scale_factor=" << available_scale_factor;
1593     return;
1594   }
1595
1596   // Fill in all missing scale factors by scaling the available bitmap.
1597   for (size_t i = 0; i < scale_factors_.size(); ++i) {
1598     int scaled_raw_id = GetRawIDByPersistentID(prs_id, scale_factors_[i]);
1599     if (image_memory_.find(scaled_raw_id) != image_memory_.end())
1600       continue;
1601     SkBitmap scaled_bitmap =
1602         CreateLowQualityResizedBitmap(available_bitmap,
1603                                       available_scale_factor,
1604                                       scale_factors_[i]);
1605     std::vector<unsigned char> bitmap_data;
1606     if (!gfx::PNGCodec::EncodeBGRASkBitmap(scaled_bitmap,
1607                                            false,
1608                                            &bitmap_data)) {
1609       NOTREACHED() << "Unable to encode theme image for prs_id="
1610                    << prs_id << " for scale_factor=" << scale_factors_[i];
1611       break;
1612     }
1613     image_memory_[scaled_raw_id] =
1614         base::RefCountedBytes::TakeVector(&bitmap_data);
1615   }
1616 }