chrome/browser/sync/glue/favicon_cache.cc

   1 // Copyright 2013 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/sync/glue/favicon_cache.h"
   6
   7 #include "base/message_loop/message_loop.h"
   8 #include "base/metrics/histogram.h"
   9 #include "chrome/browser/chrome_notification_types.h"
  10 #include "chrome/browser/favicon/favicon_service.h"
  11 #include "chrome/browser/favicon/favicon_service_factory.h"
  12 #include "chrome/browser/history/history_notifications.h"
  13 #include "chrome/browser/history/history_types.h"
  14 #include "content/public/browser/notification_details.h"
  15 #include "content/public/browser/notification_source.h"
  16 #include "sync/api/time.h"
  17 #include "sync/protocol/favicon_image_specifics.pb.h"
  18 #include "sync/protocol/favicon_tracking_specifics.pb.h"
  19 #include "sync/protocol/sync.pb.h"
  20 #include "ui/gfx/favicon_size.h"
  21
  22 namespace browser_sync {
  23
  24 // Synced favicon storage and tracking.
  25 // Note: we don't use the favicon service for storing these because these
  26 // favicons are not necessarily associated with any local navigation, and
  27 // hence would not work with the current expiration logic. We have custom
  28 // expiration logic based on visit time/bookmark status/etc.
  29 // See crbug.com/122890.
  30 struct SyncedFaviconInfo {
  31   explicit SyncedFaviconInfo(const GURL& favicon_url)
  32       : favicon_url(favicon_url),
  33         is_bookmarked(false),
  34         received_local_update(false) {}
  35
  36   // The actual favicon data.
  37   // TODO(zea): don't keep around the actual data for locally sourced
  38   // favicons (UI can access those directly).
  39   favicon_base::FaviconRawBitmapResult bitmap_data[NUM_SIZES];
  40   // The URL this favicon was loaded from.
  41   const GURL favicon_url;
  42   // Is the favicon for a bookmarked page?
  43   bool is_bookmarked;
  44   // The last time a tab needed this favicon.
  45   // Note: Do not modify this directly! It should only be modified via
  46   // UpdateFaviconVisitTime(..).
  47   base::Time last_visit_time;
  48   // Whether we've received a local update for this favicon since starting up.
  49   bool received_local_update;
  50
  51  private:
  52   DISALLOW_COPY_AND_ASSIGN(SyncedFaviconInfo);
  53 };
  54
  55 // Information for handling local favicon updates. Used in
  56 // OnFaviconDataAvailable.
  57 struct LocalFaviconUpdateInfo {
  58   LocalFaviconUpdateInfo()
  59       : new_image(false),
  60         new_tracking(false),
  61         image_needs_rewrite(false),
  62         favicon_info(NULL) {}
  63
  64   bool new_image;
  65   bool new_tracking;
  66   bool image_needs_rewrite;
  67   SyncedFaviconInfo* favicon_info;
  68 };
  69
  70 namespace {
  71
  72 // Maximum number of favicons to keep in memory (0 means no limit).
  73 const size_t kMaxFaviconsInMem = 0;
  74
  75 // Maximum width/height resolution supported.
  76 const int kMaxFaviconResolution = 16;
  77
  78 // Returns a mask of the supported favicon types.
  79 // TODO(zea): Supporting other favicons types will involve some work in the
  80 // favicon service and navigation controller. See crbug.com/181068.
  81 int SupportedFaviconTypes() { return favicon_base::FAVICON; }
  82
  83 // Returns the appropriate IconSize to use for a given gfx::Size pixel
  84 // dimensions.
  85 IconSize GetIconSizeBinFromBitmapResult(const gfx::Size& pixel_size) {
  86   int max_size =
  87       (pixel_size.width() > pixel_size.height() ?
  88        pixel_size.width() : pixel_size.height());
  89   // TODO(zea): re-enable 64p and 32p resolutions once we support them.
  90   if (max_size > 64)
  91     return SIZE_INVALID;
  92   else if (max_size > 32)
  93     return SIZE_INVALID;
  94   else if (max_size > 16)
  95     return SIZE_INVALID;
  96   else
  97     return SIZE_16;
  98 }
  99
 100 // Helper for debug statements.
 101 std::string IconSizeToString(IconSize icon_size) {
 102   switch (icon_size) {
 103     case SIZE_16:
 104       return "16";
 105     case SIZE_32:
 106       return "32";
 107     case SIZE_64:
 108       return "64";
 109     default:
 110       return "INVALID";
 111   }
 112 }
 113
 114 // Extract the favicon url from either of the favicon types.
 115 GURL GetFaviconURLFromSpecifics(const sync_pb::EntitySpecifics& specifics) {
 116   if (specifics.has_favicon_tracking())
 117     return GURL(specifics.favicon_tracking().favicon_url());
 118   else
 119     return GURL(specifics.favicon_image().favicon_url());
 120 }
 121
 122 // Convert protobuf image data into a FaviconRawBitmapResult.
 123 favicon_base::FaviconRawBitmapResult GetImageDataFromSpecifics(
 124     const sync_pb::FaviconData& favicon_data) {
 125   base::RefCountedString* temp_string =
 126       new base::RefCountedString();
 127   temp_string->data() = favicon_data.favicon();
 128   favicon_base::FaviconRawBitmapResult bitmap_result;
 129   bitmap_result.bitmap_data = temp_string;
 130   bitmap_result.pixel_size.set_height(favicon_data.height());
 131   bitmap_result.pixel_size.set_width(favicon_data.width());
 132   return bitmap_result;
 133 }
 134
 135 // Convert a FaviconRawBitmapResult into protobuf image data.
 136 void FillSpecificsWithImageData(
 137     const favicon_base::FaviconRawBitmapResult& bitmap_result,
 138     sync_pb::FaviconData* favicon_data) {
 139   if (!bitmap_result.bitmap_data.get())
 140     return;
 141   favicon_data->set_height(bitmap_result.pixel_size.height());
 142   favicon_data->set_width(bitmap_result.pixel_size.width());
 143   favicon_data->set_favicon(bitmap_result.bitmap_data->front(),
 144                             bitmap_result.bitmap_data->size());
 145 }
 146
 147 // Build a FaviconImageSpecifics from a SyncedFaviconInfo.
 148 void BuildImageSpecifics(
 149     const SyncedFaviconInfo* favicon_info,
 150     sync_pb::FaviconImageSpecifics* image_specifics) {
 151   image_specifics->set_favicon_url(favicon_info->favicon_url.spec());
 152   FillSpecificsWithImageData(favicon_info->bitmap_data[SIZE_16],
 153                              image_specifics->mutable_favicon_web());
 154   // TODO(zea): bring this back if we can handle the load.
 155   // FillSpecificsWithImageData(favicon_info->bitmap_data[SIZE_32],
 156   //                            image_specifics->mutable_favicon_web_32());
 157   // FillSpecificsWithImageData(favicon_info->bitmap_data[SIZE_64],
 158   //                            image_specifics->mutable_favicon_touch_64());
 159 }
 160
 161 // Build a FaviconTrackingSpecifics from a SyncedFaviconInfo.
 162 void BuildTrackingSpecifics(
 163     const SyncedFaviconInfo* favicon_info,
 164     sync_pb::FaviconTrackingSpecifics* tracking_specifics) {
 165   tracking_specifics->set_favicon_url(favicon_info->favicon_url.spec());
 166   tracking_specifics->set_last_visit_time_ms(
 167       syncer::TimeToProtoTime(favicon_info->last_visit_time));
 168   tracking_specifics->set_is_bookmarked(favicon_info->is_bookmarked);
 169 }
 170
 171 // Updates |favicon_info| with the image data in |bitmap_result|.
 172 bool UpdateFaviconFromBitmapResult(
 173     const favicon_base::FaviconRawBitmapResult& bitmap_result,
 174     SyncedFaviconInfo* favicon_info) {
 175   DCHECK_EQ(favicon_info->favicon_url, bitmap_result.icon_url);
 176   if (!bitmap_result.is_valid()) {
 177     DVLOG(1) << "Received invalid favicon at " << bitmap_result.icon_url.spec();
 178     return false;
 179   }
 180
 181   IconSize icon_size = GetIconSizeBinFromBitmapResult(
 182       bitmap_result.pixel_size);
 183   if (icon_size == SIZE_INVALID) {
 184     DVLOG(1) << "Ignoring unsupported resolution "
 185              << bitmap_result.pixel_size.height() << "x"
 186              << bitmap_result.pixel_size.width();
 187     return false;
 188   } else if (!favicon_info->bitmap_data[icon_size].bitmap_data.get() ||
 189              !favicon_info->received_local_update) {
 190     DVLOG(1) << "Storing " << IconSizeToString(icon_size) << "p"
 191              << " favicon for " << favicon_info->favicon_url.spec()
 192              << " with size " << bitmap_result.bitmap_data->size()
 193              << " bytes.";
 194     favicon_info->bitmap_data[icon_size] = bitmap_result;
 195     favicon_info->received_local_update = true;
 196     return true;
 197   } else {
 198     // We only allow updating the image data once per restart.
 199     DVLOG(2) << "Ignoring local update for " << bitmap_result.icon_url.spec();
 200     return false;
 201   }
 202 }
 203
 204 bool FaviconInfoHasImages(const SyncedFaviconInfo& favicon_info) {
 205   return favicon_info.bitmap_data[SIZE_16].bitmap_data.get() ||
 206          favicon_info.bitmap_data[SIZE_32].bitmap_data.get() ||
 207          favicon_info.bitmap_data[SIZE_64].bitmap_data.get();
 208 }
 209
 210 bool FaviconInfoHasTracking(const SyncedFaviconInfo& favicon_info) {
 211   return !favicon_info.last_visit_time.is_null();
 212 }
 213
 214 bool FaviconInfoHasValidTypeData(const SyncedFaviconInfo& favicon_info,
 215                              syncer::ModelType type) {
 216   if (type == syncer::FAVICON_IMAGES)
 217     return FaviconInfoHasImages(favicon_info);
 218   else if (type == syncer::FAVICON_TRACKING)
 219     return FaviconInfoHasTracking(favicon_info);
 220   NOTREACHED();
 221   return false;
 222 }
 223
 224 }  // namespace
 225
 226 FaviconCache::FaviconCache(Profile* profile, int max_sync_favicon_limit)
 227     : profile_(profile),
 228       max_sync_favicon_limit_(max_sync_favicon_limit),
 229       weak_ptr_factory_(this) {
 230   notification_registrar_.Add(this,
 231                               chrome::NOTIFICATION_HISTORY_URLS_DELETED,
 232                               content::Source<Profile>(profile_));
 233   DVLOG(1) << "Setting favicon limit to " << max_sync_favicon_limit;
 234 }
 235
 236 FaviconCache::~FaviconCache() {}
 237
 238 syncer::SyncMergeResult FaviconCache::MergeDataAndStartSyncing(
 239     syncer::ModelType type,
 240     const syncer::SyncDataList& initial_sync_data,
 241     scoped_ptr<syncer::SyncChangeProcessor> sync_processor,
 242     scoped_ptr<syncer::SyncErrorFactory> error_handler) {
 243   DCHECK(type == syncer::FAVICON_IMAGES || type == syncer::FAVICON_TRACKING);
 244   if (type == syncer::FAVICON_IMAGES)
 245     favicon_images_sync_processor_ = sync_processor.Pass();
 246   else
 247     favicon_tracking_sync_processor_ = sync_processor.Pass();
 248
 249   syncer::SyncMergeResult merge_result(type);
 250   merge_result.set_num_items_before_association(synced_favicons_.size());
 251   std::set<GURL> unsynced_favicon_urls;
 252   for (FaviconMap::const_iterator iter = synced_favicons_.begin();
 253        iter != synced_favicons_.end(); ++iter) {
 254     if (FaviconInfoHasValidTypeData(*(iter->second), type))
 255       unsynced_favicon_urls.insert(iter->first);
 256   }
 257
 258   syncer::SyncChangeList local_changes;
 259   for (syncer::SyncDataList::const_iterator iter = initial_sync_data.begin();
 260        iter != initial_sync_data.end(); ++iter) {
 261     GURL remote_url = GetFaviconURLFromSpecifics(iter->GetSpecifics());
 262     GURL favicon_url = GetLocalFaviconFromSyncedData(*iter);
 263     if (favicon_url.is_valid()) {
 264       unsynced_favicon_urls.erase(favicon_url);
 265       MergeSyncFavicon(*iter, &local_changes);
 266       merge_result.set_num_items_modified(
 267           merge_result.num_items_modified() + 1);
 268     } else {
 269       AddLocalFaviconFromSyncedData(*iter);
 270       merge_result.set_num_items_added(merge_result.num_items_added() + 1);
 271     }
 272   }
 273
 274   // Rather than trigger a bunch of deletions when we set up sync, we drop
 275   // local favicons. Those pages that are currently open are likely to result in
 276   // loading new favicons/refreshing old favicons anyways, at which point
 277   // they'll be re-added and the appropriate synced favicons will be evicted.
 278   // TODO(zea): implement a smarter ordering of the which favicons to drop.
 279   int available_favicons = max_sync_favicon_limit_ - initial_sync_data.size();
 280   UMA_HISTOGRAM_BOOLEAN("Sync.FaviconsAvailableAtMerge",
 281                         available_favicons > 0);
 282   for (std::set<GURL>::const_iterator iter = unsynced_favicon_urls.begin();
 283        iter != unsynced_favicon_urls.end(); ++iter) {
 284     if (available_favicons > 0) {
 285       local_changes.push_back(
 286           syncer::SyncChange(FROM_HERE,
 287                              syncer::SyncChange::ACTION_ADD,
 288                              CreateSyncDataFromLocalFavicon(type, *iter)));
 289       available_favicons--;
 290     } else {
 291       FaviconMap::iterator favicon_iter = synced_favicons_.find(*iter);
 292       DVLOG(1) << "Dropping local favicon "
 293                << favicon_iter->second->favicon_url.spec();
 294       DropPartialFavicon(favicon_iter, type);
 295       merge_result.set_num_items_deleted(merge_result.num_items_deleted() + 1);
 296     }
 297   }
 298   UMA_HISTOGRAM_COUNTS_10000("Sync.FaviconCount", synced_favicons_.size());
 299   merge_result.set_num_items_after_association(synced_favicons_.size());
 300
 301   if (type == syncer::FAVICON_IMAGES) {
 302     favicon_images_sync_processor_->ProcessSyncChanges(FROM_HERE,
 303                                                        local_changes);
 304   } else {
 305     favicon_tracking_sync_processor_->ProcessSyncChanges(FROM_HERE,
 306                                                          local_changes);
 307   }
 308   return merge_result;
 309 }
 310
 311 void FaviconCache::StopSyncing(syncer::ModelType type) {
 312   favicon_images_sync_processor_.reset();
 313   favicon_tracking_sync_processor_.reset();
 314   cancelable_task_tracker_.TryCancelAll();
 315   page_task_map_.clear();
 316 }
 317
 318 syncer::SyncDataList FaviconCache::GetAllSyncData(syncer::ModelType type)
 319     const {
 320   syncer::SyncDataList data_list;
 321   for (FaviconMap::const_iterator iter = synced_favicons_.begin();
 322        iter != synced_favicons_.end(); ++iter) {
 323     if ((type == syncer::FAVICON_IMAGES &&
 324          FaviconInfoHasImages(*iter->second)) ||
 325         (type == syncer::FAVICON_TRACKING &&
 326          FaviconInfoHasTracking(*iter->second))) {
 327       data_list.push_back(CreateSyncDataFromLocalFavicon(type, iter->first));
 328     }
 329   }
 330   return data_list;
 331 }
 332
 333 syncer::SyncError FaviconCache::ProcessSyncChanges(
 334     const tracked_objects::Location& from_here,
 335     const syncer::SyncChangeList& change_list) {
 336   if (!favicon_images_sync_processor_.get() ||
 337       !favicon_tracking_sync_processor_.get()) {
 338     return syncer::SyncError(FROM_HERE,
 339                              syncer::SyncError::DATATYPE_ERROR,
 340                              "One or both favicon types disabled.",
 341                              change_list[0].sync_data().GetDataType());
 342   }
 343
 344   syncer::SyncChangeList new_changes;
 345   syncer::SyncError error;
 346   syncer::ModelType type = syncer::UNSPECIFIED;
 347   for (syncer::SyncChangeList::const_iterator iter = change_list.begin();
 348       iter != change_list.end(); ++iter) {
 349     type = iter->sync_data().GetDataType();
 350     DCHECK(type == syncer::FAVICON_IMAGES || type == syncer::FAVICON_TRACKING);
 351     GURL favicon_url =
 352         GetFaviconURLFromSpecifics(iter->sync_data().GetSpecifics());
 353     if (!favicon_url.is_valid()) {
 354       error.Reset(FROM_HERE, "Received invalid favicon url.", type);
 355       break;
 356     }
 357     FaviconMap::iterator favicon_iter = synced_favicons_.find(favicon_url);
 358     if (iter->change_type() == syncer::SyncChange::ACTION_DELETE) {
 359       if (favicon_iter == synced_favicons_.end()) {
 360         // Two clients might wind up deleting different parts of the same
 361         // favicon, so ignore this.
 362         continue;
 363       } else {
 364         DVLOG(1) << "Deleting favicon at " << favicon_url.spec();
 365         // If we only have partial data for the favicon (which implies orphaned
 366         // nodes), delete the local favicon only if the type corresponds to the
 367         // partial data we have. If we do have orphaned nodes, we rely on the
 368         // expiration logic to remove them eventually.
 369         DropPartialFavicon(favicon_iter, type);
 370       }
 371     } else if (iter->change_type() == syncer::SyncChange::ACTION_UPDATE ||
 372                iter->change_type() == syncer::SyncChange::ACTION_ADD) {
 373       // Adds and updates are treated the same due to the lack of strong
 374       // consistency (it's possible we'll receive an update for a tracking info
 375       // before we've received the add for the image, and should handle both
 376       // gracefully).
 377       if (favicon_iter == synced_favicons_.end()) {
 378         DVLOG(1) << "Adding favicon at " << favicon_url.spec();
 379         AddLocalFaviconFromSyncedData(iter->sync_data());
 380       } else {
 381         DVLOG(1) << "Updating favicon at " << favicon_url.spec();
 382         MergeSyncFavicon(iter->sync_data(), &new_changes);
 383       }
 384     } else {
 385       error.Reset(FROM_HERE, "Invalid action received.", type);
 386       break;
 387     }
 388   }
 389
 390   // Note: we deliberately do not expire favicons here. If we received new
 391   // favicons and are now over the limit, the next local favicon change will
 392   // trigger the necessary expiration.
 393   if (!error.IsSet() && !new_changes.empty()) {
 394     if (type == syncer::FAVICON_IMAGES) {
 395         favicon_images_sync_processor_->ProcessSyncChanges(FROM_HERE,
 396                                                            new_changes);
 397     } else {
 398         favicon_tracking_sync_processor_->ProcessSyncChanges(FROM_HERE,
 399                                                              new_changes);
 400     }
 401   }
 402
 403   return error;
 404 }
 405
 406 void FaviconCache::OnPageFaviconUpdated(const GURL& page_url) {
 407   DCHECK(page_url.is_valid());
 408
 409   // If a favicon load is already happening for this url, let it finish.
 410   if (page_task_map_.find(page_url) != page_task_map_.end())
 411     return;
 412
 413   PageFaviconMap::const_iterator url_iter = page_favicon_map_.find(page_url);
 414   if (url_iter != page_favicon_map_.end()) {
 415     FaviconMap::const_iterator icon_iter =
 416         synced_favicons_.find(url_iter->second);
 417     // TODO(zea): consider what to do when only a subset of supported
 418     // resolutions are available.
 419     if (icon_iter != synced_favicons_.end() &&
 420         icon_iter->second->bitmap_data[SIZE_16].bitmap_data.get()) {
 421       DVLOG(2) << "Using cached favicon url for " << page_url.spec()
 422                << ": " << icon_iter->second->favicon_url.spec();
 423       UpdateFaviconVisitTime(icon_iter->second->favicon_url, base::Time::Now());
 424       UpdateSyncState(icon_iter->second->favicon_url,
 425                       syncer::SyncChange::ACTION_INVALID,
 426                       syncer::SyncChange::ACTION_UPDATE);
 427       return;
 428     }
 429   }
 430
 431   DVLOG(1) << "Triggering favicon load for url " << page_url.spec();
 432
 433   if (!profile_) {
 434     page_task_map_[page_url] = 0;  // For testing only.
 435     return;
 436   }
 437   FaviconService* favicon_service =
 438       FaviconServiceFactory::GetForProfile(profile_, Profile::EXPLICIT_ACCESS);
 439   if (!favicon_service)
 440     return;
 441   // TODO(zea): This appears to only fetch one favicon (best match based on
 442   // desired_size_in_dip). Figure out a way to fetch all favicons we support.
 443   // See crbug.com/181068.
 444   base::CancelableTaskTracker::TaskId id =
 445       favicon_service->GetFaviconForPageURL(
 446           page_url,
 447           SupportedFaviconTypes(),
 448           kMaxFaviconResolution,
 449           base::Bind(&FaviconCache::OnFaviconDataAvailable,
 450                      weak_ptr_factory_.GetWeakPtr(),
 451                      page_url),
 452           &cancelable_task_tracker_);
 453   page_task_map_[page_url] = id;
 454 }
 455
 456 void FaviconCache::OnFaviconVisited(const GURL& page_url,
 457                                     const GURL& favicon_url) {
 458   DCHECK(page_url.is_valid());
 459   if (!favicon_url.is_valid() ||
 460       synced_favicons_.find(favicon_url) == synced_favicons_.end()) {
 461     // TODO(zea): consider triggering a favicon load if we have some but not
 462     // all desired resolutions?
 463     OnPageFaviconUpdated(page_url);
 464     return;
 465   }
 466
 467   DVLOG(1) << "Associating " << page_url.spec() << " with favicon at "
 468            << favicon_url.spec() << " and marking visited.";
 469   page_favicon_map_[page_url] = favicon_url;
 470   bool had_tracking = FaviconInfoHasTracking(
 471       *synced_favicons_.find(favicon_url)->second);
 472   UpdateFaviconVisitTime(favicon_url, base::Time::Now());
 473
 474   UpdateSyncState(favicon_url,
 475                   syncer::SyncChange::ACTION_INVALID,
 476                   (had_tracking ?
 477                    syncer::SyncChange::ACTION_UPDATE :
 478                    syncer::SyncChange::ACTION_ADD));
 479 }
 480
 481 bool FaviconCache::GetSyncedFaviconForFaviconURL(
 482     const GURL& favicon_url,
 483     scoped_refptr<base::RefCountedMemory>* favicon_png) const {
 484   if (!favicon_url.is_valid())
 485     return false;
 486   FaviconMap::const_iterator iter = synced_favicons_.find(favicon_url);
 487
 488   UMA_HISTOGRAM_BOOLEAN("Sync.FaviconCacheLookupSucceeded",
 489                         iter != synced_favicons_.end());
 490   if (iter == synced_favicons_.end())
 491     return false;
 492
 493   // TODO(zea): support getting other resolutions.
 494   if (!iter->second->bitmap_data[SIZE_16].bitmap_data.get())
 495     return false;
 496
 497   *favicon_png = iter->second->bitmap_data[SIZE_16].bitmap_data;
 498   return true;
 499 }
 500
 501 bool FaviconCache::GetSyncedFaviconForPageURL(
 502     const GURL& page_url,
 503     scoped_refptr<base::RefCountedMemory>* favicon_png) const {
 504   if (!page_url.is_valid())
 505     return false;
 506   PageFaviconMap::const_iterator iter = page_favicon_map_.find(page_url);
 507
 508   if (iter == page_favicon_map_.end())
 509     return false;
 510
 511   return GetSyncedFaviconForFaviconURL(iter->second, favicon_png);
 512 }
 513
 514 void FaviconCache::OnReceivedSyncFavicon(const GURL& page_url,
 515                                          const GURL& icon_url,
 516                                          const std::string& icon_bytes,
 517                                          int64 visit_time_ms) {
 518   if (!icon_url.is_valid() || !page_url.is_valid() || icon_url.SchemeIs("data"))
 519     return;
 520   DVLOG(1) << "Associating " << page_url.spec() << " with favicon at "
 521            << icon_url.spec();
 522   page_favicon_map_[page_url] = icon_url;
 523
 524   // If there is no actual image, it means there either is no synced
 525   // favicon, or it's on its way (race condition).
 526   // TODO(zea): potentially trigger a favicon web download here (delayed?).
 527   if (icon_bytes.size() == 0)
 528     return;
 529
 530   // Post a task to do the actual association because this method may have been
 531   // called while in a transaction.
 532   base::MessageLoop::current()->PostTask(
 533       FROM_HERE,
 534       base::Bind(&FaviconCache::OnReceivedSyncFaviconImpl,
 535                  weak_ptr_factory_.GetWeakPtr(),
 536                  icon_url,
 537                  icon_bytes,
 538                  visit_time_ms));
 539 }
 540
 541 void FaviconCache::OnReceivedSyncFaviconImpl(
 542     const GURL& icon_url,
 543     const std::string& icon_bytes,
 544     int64 visit_time_ms) {
 545   // If this favicon is already synced, do nothing else.
 546   if (synced_favicons_.find(icon_url) != synced_favicons_.end())
 547     return;
 548
 549   // Don't add any more favicons once we hit our in memory limit.
 550   // TODO(zea): UMA this.
 551   if (kMaxFaviconsInMem != 0 && synced_favicons_.size() > kMaxFaviconsInMem)
 552     return;
 553
 554   SyncedFaviconInfo* favicon_info = GetFaviconInfo(icon_url);
 555   if (!favicon_info)
 556     return;  // We reached the in-memory limit.
 557   base::RefCountedString* temp_string = new base::RefCountedString();
 558   temp_string->data() = icon_bytes;
 559   favicon_info->bitmap_data[SIZE_16].bitmap_data = temp_string;
 560   // We assume legacy favicons are 16x16.
 561   favicon_info->bitmap_data[SIZE_16].pixel_size.set_width(16);
 562   favicon_info->bitmap_data[SIZE_16].pixel_size.set_height(16);
 563   bool added_tracking = !FaviconInfoHasTracking(*favicon_info);
 564   UpdateFaviconVisitTime(icon_url,
 565                          syncer::ProtoTimeToTime(visit_time_ms));
 566
 567   UpdateSyncState(icon_url,
 568                   syncer::SyncChange::ACTION_ADD,
 569                   (added_tracking ?
 570                    syncer::SyncChange::ACTION_ADD :
 571                    syncer::SyncChange::ACTION_UPDATE));
 572 }
 573
 574 void FaviconCache::Observe(int type,
 575                            const content::NotificationSource& source,
 576                            const content::NotificationDetails& details) {
 577   DCHECK_EQ(type, chrome::NOTIFICATION_HISTORY_URLS_DELETED);
 578
 579   content::Details<history::URLsDeletedDetails> deleted_details(details);
 580
 581   // We only care about actual user (or sync) deletions.
 582   if (deleted_details->expired)
 583     return;
 584
 585   if (!deleted_details->all_history) {
 586     DeleteSyncedFavicons(deleted_details->favicon_urls);
 587     return;
 588   }
 589
 590   // All history was cleared: just delete all favicons.
 591   DVLOG(1) << "History clear detected, deleting all synced favicons.";
 592   syncer::SyncChangeList image_deletions, tracking_deletions;
 593   while (!synced_favicons_.empty()) {
 594     DeleteSyncedFavicon(synced_favicons_.begin(),
 595                         &image_deletions,
 596                         &tracking_deletions);
 597   }
 598
 599   if (favicon_images_sync_processor_.get()) {
 600     favicon_images_sync_processor_->ProcessSyncChanges(FROM_HERE,
 601                                                        image_deletions);
 602   }
 603   if (favicon_tracking_sync_processor_.get()) {
 604     favicon_tracking_sync_processor_->ProcessSyncChanges(FROM_HERE,
 605                                                          tracking_deletions);
 606   }
 607 }
 608
 609 bool FaviconCache::FaviconRecencyFunctor::operator()(
 610     const linked_ptr<SyncedFaviconInfo>& lhs,
 611     const linked_ptr<SyncedFaviconInfo>& rhs) const {
 612   // TODO(zea): incorporate bookmarked status here once we care about it.
 613   if (lhs->last_visit_time < rhs->last_visit_time)
 614     return true;
 615   else if (lhs->last_visit_time == rhs->last_visit_time)
 616     return lhs->favicon_url.spec() < rhs->favicon_url.spec();
 617   return false;
 618 }
 619
 620 void FaviconCache::OnFaviconDataAvailable(
 621     const GURL& page_url,
 622     const std::vector<favicon_base::FaviconRawBitmapResult>& bitmap_results) {
 623   PageTaskMap::iterator page_iter = page_task_map_.find(page_url);
 624   if (page_iter == page_task_map_.end())
 625     return;
 626   page_task_map_.erase(page_iter);
 627
 628   if (bitmap_results.size() == 0) {
 629     // Either the favicon isn't loaded yet or there is no valid favicon.
 630     // We already cleared the task id, so just return.
 631     DVLOG(1) << "Favicon load failed for page " << page_url.spec();
 632     return;
 633   }
 634
 635   base::Time now = base::Time::Now();
 636   std::map<GURL, LocalFaviconUpdateInfo> favicon_updates;
 637   for (size_t i = 0; i < bitmap_results.size(); ++i) {
 638     const favicon_base::FaviconRawBitmapResult& bitmap_result =
 639         bitmap_results[i];
 640     GURL favicon_url = bitmap_result.icon_url;
 641     if (!favicon_url.is_valid() || favicon_url.SchemeIs("data"))
 642       continue;  // Can happen if the page is still loading.
 643
 644     SyncedFaviconInfo* favicon_info = GetFaviconInfo(favicon_url);
 645     if (!favicon_info)
 646       return;  // We reached the in-memory limit.
 647
 648     favicon_updates[favicon_url].new_image |=
 649         !FaviconInfoHasImages(*favicon_info);
 650     favicon_updates[favicon_url].new_tracking |=
 651         !FaviconInfoHasTracking(*favicon_info);
 652     favicon_updates[favicon_url].image_needs_rewrite |=
 653         UpdateFaviconFromBitmapResult(bitmap_result, favicon_info);
 654     favicon_updates[favicon_url].favicon_info = favicon_info;
 655   }
 656
 657   for (std::map<GURL, LocalFaviconUpdateInfo>::const_iterator
 658            iter = favicon_updates.begin(); iter != favicon_updates.end();
 659        ++iter) {
 660     SyncedFaviconInfo* favicon_info = iter->second.favicon_info;
 661     const GURL& favicon_url = favicon_info->favicon_url;
 662
 663     // TODO(zea): support multiple favicon urls per page.
 664     page_favicon_map_[page_url] = favicon_url;
 665
 666     if (!favicon_info->last_visit_time.is_null()) {
 667       UMA_HISTOGRAM_COUNTS_10000(
 668           "Sync.FaviconVisitPeriod",
 669           (now - favicon_info->last_visit_time).InHours());
 670     }
 671     favicon_info->received_local_update = true;
 672     UpdateFaviconVisitTime(favicon_url, now);
 673
 674     syncer::SyncChange::SyncChangeType image_change =
 675         syncer::SyncChange::ACTION_INVALID;
 676     if (iter->second.new_image)
 677       image_change = syncer::SyncChange::ACTION_ADD;
 678     else if (iter->second.image_needs_rewrite)
 679       image_change = syncer::SyncChange::ACTION_UPDATE;
 680     syncer::SyncChange::SyncChangeType tracking_change =
 681         syncer::SyncChange::ACTION_UPDATE;
 682     if (iter->second.new_tracking)
 683       tracking_change = syncer::SyncChange::ACTION_ADD;
 684     UpdateSyncState(favicon_url, image_change, tracking_change);
 685   }
 686 }
 687
 688 void FaviconCache::UpdateSyncState(
 689     const GURL& icon_url,
 690     syncer::SyncChange::SyncChangeType image_change_type,
 691     syncer::SyncChange::SyncChangeType tracking_change_type) {
 692   DCHECK(icon_url.is_valid());
 693   // It's possible that we'll receive a favicon update before both types
 694   // have finished setting up. In that case ignore the update.
 695   // TODO(zea): consider tracking these skipped updates somehow?
 696   if (!favicon_images_sync_processor_.get() ||
 697       !favicon_tracking_sync_processor_.get()) {
 698     return;
 699   }
 700
 701   FaviconMap::const_iterator iter = synced_favicons_.find(icon_url);
 702   DCHECK(iter != synced_favicons_.end());
 703   const SyncedFaviconInfo* favicon_info = iter->second.get();
 704
 705   syncer::SyncChangeList image_changes;
 706   syncer::SyncChangeList tracking_changes;
 707   if (image_change_type != syncer::SyncChange::ACTION_INVALID) {
 708     sync_pb::EntitySpecifics new_specifics;
 709     sync_pb::FaviconImageSpecifics* image_specifics =
 710         new_specifics.mutable_favicon_image();
 711     BuildImageSpecifics(favicon_info, image_specifics);
 712
 713     image_changes.push_back(
 714         syncer::SyncChange(FROM_HERE,
 715                            image_change_type,
 716                            syncer::SyncData::CreateLocalData(
 717                                icon_url.spec(),
 718                                icon_url.spec(),
 719                                new_specifics)));
 720   }
 721   if (tracking_change_type != syncer::SyncChange::ACTION_INVALID) {
 722     sync_pb::EntitySpecifics new_specifics;
 723     sync_pb::FaviconTrackingSpecifics* tracking_specifics =
 724         new_specifics.mutable_favicon_tracking();
 725     BuildTrackingSpecifics(favicon_info, tracking_specifics);
 726
 727     tracking_changes.push_back(
 728         syncer::SyncChange(FROM_HERE,
 729                            tracking_change_type,
 730                            syncer::SyncData::CreateLocalData(
 731                                icon_url.spec(),
 732                                icon_url.spec(),
 733                                new_specifics)));
 734   }
 735   ExpireFaviconsIfNecessary(&image_changes, &tracking_changes);
 736   if (!image_changes.empty()) {
 737     favicon_images_sync_processor_->ProcessSyncChanges(FROM_HERE,
 738                                                        image_changes);
 739   }
 740   if (!tracking_changes.empty()) {
 741     favicon_tracking_sync_processor_->ProcessSyncChanges(FROM_HERE,
 742                                                          tracking_changes);
 743   }
 744 }
 745
 746 SyncedFaviconInfo* FaviconCache::GetFaviconInfo(
 747     const GURL& icon_url) {
 748   DCHECK_EQ(recent_favicons_.size(), synced_favicons_.size());
 749   if (synced_favicons_.count(icon_url) != 0)
 750     return synced_favicons_[icon_url].get();
 751
 752   // TODO(zea): implement in-memory eviction.
 753   DVLOG(1) << "Adding favicon info for " << icon_url.spec();
 754   SyncedFaviconInfo* favicon_info = new SyncedFaviconInfo(icon_url);
 755   synced_favicons_[icon_url] = make_linked_ptr(favicon_info);
 756   recent_favicons_.insert(synced_favicons_[icon_url]);
 757   DCHECK_EQ(recent_favicons_.size(), synced_favicons_.size());
 758   return favicon_info;
 759 }
 760
 761 void FaviconCache::UpdateFaviconVisitTime(const GURL& icon_url,
 762                                           base::Time time) {
 763   DCHECK_EQ(recent_favicons_.size(), synced_favicons_.size());
 764   FaviconMap::const_iterator iter = synced_favicons_.find(icon_url);
 765   DCHECK(iter != synced_favicons_.end());
 766   if (iter->second->last_visit_time >= time)
 767     return;
 768   // Erase, update the time, then re-insert to maintain ordering.
 769   recent_favicons_.erase(iter->second);
 770   DVLOG(1) << "Updating " << icon_url.spec() << " visit time to "
 771            << syncer::GetTimeDebugString(time);
 772   iter->second->last_visit_time = time;
 773   recent_favicons_.insert(iter->second);
 774
 775   if (VLOG_IS_ON(2)) {
 776     for (RecencySet::const_iterator iter = recent_favicons_.begin();
 777          iter != recent_favicons_.end(); ++iter) {
 778       DVLOG(2) << "Favicon " << iter->get()->favicon_url.spec() << ": "
 779                << syncer::GetTimeDebugString(iter->get()->last_visit_time);
 780     }
 781   }
 782   DCHECK_EQ(recent_favicons_.size(), synced_favicons_.size());
 783 }
 784
 785 void FaviconCache::ExpireFaviconsIfNecessary(
 786     syncer::SyncChangeList* image_changes,
 787     syncer::SyncChangeList* tracking_changes) {
 788   DCHECK_EQ(recent_favicons_.size(), synced_favicons_.size());
 789   // TODO(zea): once we have in-memory eviction, we'll need to track sync
 790   // favicon count separately from the synced_favicons_/recent_favicons_.
 791
 792   // Iterate until we've removed the necessary amount. |recent_favicons_| is
 793   // already in recency order, so just start from the beginning.
 794   // TODO(zea): to reduce thrashing, consider removing more than the minimum.
 795   while (recent_favicons_.size() > max_sync_favicon_limit_) {
 796     linked_ptr<SyncedFaviconInfo> candidate = *recent_favicons_.begin();
 797     DVLOG(1) << "Expiring favicon " << candidate->favicon_url.spec();
 798     DeleteSyncedFavicon(synced_favicons_.find(candidate->favicon_url),
 799                         image_changes,
 800                         tracking_changes);
 801   }
 802   DCHECK_EQ(recent_favicons_.size(), synced_favicons_.size());
 803 }
 804
 805 GURL FaviconCache::GetLocalFaviconFromSyncedData(
 806     const syncer::SyncData& sync_favicon) const {
 807   syncer::ModelType type = sync_favicon.GetDataType();
 808   DCHECK(type == syncer::FAVICON_IMAGES || type == syncer::FAVICON_TRACKING);
 809   GURL favicon_url = GetFaviconURLFromSpecifics(sync_favicon.GetSpecifics());
 810   return (synced_favicons_.count(favicon_url) > 0 ? favicon_url : GURL());
 811 }
 812
 813 void FaviconCache::MergeSyncFavicon(const syncer::SyncData& sync_favicon,
 814                                     syncer::SyncChangeList* sync_changes) {
 815   syncer::ModelType type = sync_favicon.GetDataType();
 816   DCHECK(type == syncer::FAVICON_IMAGES || type == syncer::FAVICON_TRACKING);
 817   sync_pb::EntitySpecifics new_specifics;
 818   GURL favicon_url = GetFaviconURLFromSpecifics(sync_favicon.GetSpecifics());
 819   FaviconMap::const_iterator iter = synced_favicons_.find(favicon_url);
 820   DCHECK(iter != synced_favicons_.end());
 821   SyncedFaviconInfo* favicon_info = iter->second.get();
 822   if (type == syncer::FAVICON_IMAGES) {
 823     sync_pb::FaviconImageSpecifics image_specifics =
 824         sync_favicon.GetSpecifics().favicon_image();
 825
 826     // Remote image data always clobbers local image data.
 827     bool needs_update = false;
 828     if (image_specifics.has_favicon_web()) {
 829       favicon_info->bitmap_data[SIZE_16] = GetImageDataFromSpecifics(
 830           image_specifics.favicon_web());
 831     } else if (favicon_info->bitmap_data[SIZE_16].bitmap_data.get()) {
 832       needs_update = true;
 833     }
 834     if (image_specifics.has_favicon_web_32()) {
 835       favicon_info->bitmap_data[SIZE_32] = GetImageDataFromSpecifics(
 836           image_specifics.favicon_web_32());
 837     } else if (favicon_info->bitmap_data[SIZE_32].bitmap_data.get()) {
 838       needs_update = true;
 839     }
 840     if (image_specifics.has_favicon_touch_64()) {
 841       favicon_info->bitmap_data[SIZE_64] = GetImageDataFromSpecifics(
 842           image_specifics.favicon_touch_64());
 843     } else if (favicon_info->bitmap_data[SIZE_64].bitmap_data.get()) {
 844       needs_update = true;
 845     }
 846
 847     if (needs_update)
 848       BuildImageSpecifics(favicon_info, new_specifics.mutable_favicon_image());
 849   } else {
 850     sync_pb::FaviconTrackingSpecifics tracking_specifics =
 851         sync_favicon.GetSpecifics().favicon_tracking();
 852
 853     // Tracking data is merged, such that bookmark data is the logical OR
 854     // of the two, and last visit time is the most recent.
 855
 856     base::Time last_visit =  syncer::ProtoTimeToTime(
 857         tracking_specifics.last_visit_time_ms());
 858     // Due to crbug.com/258196, there are tracking nodes out there with
 859     // null visit times. If this is one of those, artificially make it a valid
 860     // visit time, so we know the node exists and update it properly on the next
 861     // real visit.
 862     if (last_visit.is_null())
 863       last_visit = last_visit + base::TimeDelta::FromMilliseconds(1);
 864     UpdateFaviconVisitTime(favicon_url, last_visit);
 865     favicon_info->is_bookmarked = (favicon_info->is_bookmarked ||
 866                                    tracking_specifics.is_bookmarked());
 867
 868     if (syncer::TimeToProtoTime(favicon_info->last_visit_time) !=
 869             tracking_specifics.last_visit_time_ms() ||
 870         favicon_info->is_bookmarked != tracking_specifics.is_bookmarked()) {
 871       BuildTrackingSpecifics(favicon_info,
 872                              new_specifics.mutable_favicon_tracking());
 873     }
 874     DCHECK(!favicon_info->last_visit_time.is_null());
 875   }
 876
 877   if (new_specifics.has_favicon_image() ||
 878       new_specifics.has_favicon_tracking()) {
 879     sync_changes->push_back(syncer::SyncChange(
 880         FROM_HERE,
 881         syncer::SyncChange::ACTION_UPDATE,
 882         syncer::SyncData::CreateLocalData(favicon_url.spec(),
 883                                           favicon_url.spec(),
 884                                           new_specifics)));
 885   }
 886 }
 887
 888 void FaviconCache::AddLocalFaviconFromSyncedData(
 889     const syncer::SyncData& sync_favicon) {
 890   syncer::ModelType type = sync_favicon.GetDataType();
 891   DCHECK(type == syncer::FAVICON_IMAGES || type == syncer::FAVICON_TRACKING);
 892   if (type == syncer::FAVICON_IMAGES) {
 893     sync_pb::FaviconImageSpecifics image_specifics =
 894         sync_favicon.GetSpecifics().favicon_image();
 895     GURL favicon_url = GURL(image_specifics.favicon_url());
 896     DCHECK(favicon_url.is_valid());
 897     DCHECK(!synced_favicons_.count(favicon_url));
 898
 899     SyncedFaviconInfo* favicon_info = GetFaviconInfo(favicon_url);
 900     if (!favicon_info)
 901       return;  // We reached the in-memory limit.
 902     if (image_specifics.has_favicon_web()) {
 903       favicon_info->bitmap_data[SIZE_16] = GetImageDataFromSpecifics(
 904           image_specifics.favicon_web());
 905     }
 906     if (image_specifics.has_favicon_web_32()) {
 907       favicon_info->bitmap_data[SIZE_32] = GetImageDataFromSpecifics(
 908           image_specifics.favicon_web_32());
 909     }
 910     if (image_specifics.has_favicon_touch_64()) {
 911       favicon_info->bitmap_data[SIZE_64] = GetImageDataFromSpecifics(
 912           image_specifics.favicon_touch_64());
 913     }
 914   } else {
 915     sync_pb::FaviconTrackingSpecifics tracking_specifics =
 916         sync_favicon.GetSpecifics().favicon_tracking();
 917     GURL favicon_url = GURL(tracking_specifics.favicon_url());
 918     DCHECK(favicon_url.is_valid());
 919     DCHECK(!synced_favicons_.count(favicon_url));
 920
 921     SyncedFaviconInfo* favicon_info = GetFaviconInfo(favicon_url);
 922     if (!favicon_info)
 923       return;  // We reached the in-memory limit.
 924     base::Time last_visit =  syncer::ProtoTimeToTime(
 925         tracking_specifics.last_visit_time_ms());
 926     // Due to crbug.com/258196, there are tracking nodes out there with
 927     // null visit times. If this is one of those, artificially make it a valid
 928     // visit time, so we know the node exists and update it properly on the next
 929     // real visit.
 930     if (last_visit.is_null())
 931       last_visit = last_visit + base::TimeDelta::FromMilliseconds(1);
 932     UpdateFaviconVisitTime(favicon_url, last_visit);
 933     favicon_info->is_bookmarked = tracking_specifics.is_bookmarked();
 934     DCHECK(!favicon_info->last_visit_time.is_null());
 935   }
 936 }
 937
 938 syncer::SyncData FaviconCache::CreateSyncDataFromLocalFavicon(
 939     syncer::ModelType type,
 940     const GURL& favicon_url) const {
 941   DCHECK(type == syncer::FAVICON_IMAGES || type == syncer::FAVICON_TRACKING);
 942   DCHECK(favicon_url.is_valid());
 943   FaviconMap::const_iterator iter = synced_favicons_.find(favicon_url);
 944   DCHECK(iter != synced_favicons_.end());
 945   SyncedFaviconInfo* favicon_info = iter->second.get();
 946
 947   syncer::SyncData data;
 948   sync_pb::EntitySpecifics specifics;
 949   if (type == syncer::FAVICON_IMAGES) {
 950     sync_pb::FaviconImageSpecifics* image_specifics =
 951         specifics.mutable_favicon_image();
 952     BuildImageSpecifics(favicon_info, image_specifics);
 953   } else {
 954     sync_pb::FaviconTrackingSpecifics* tracking_specifics =
 955         specifics.mutable_favicon_tracking();
 956     BuildTrackingSpecifics(favicon_info, tracking_specifics);
 957   }
 958   data = syncer::SyncData::CreateLocalData(favicon_url.spec(),
 959                                            favicon_url.spec(),
 960                                            specifics);
 961   return data;
 962 }
 963
 964 void FaviconCache::DeleteSyncedFavicons(const std::set<GURL>& favicon_urls) {
 965   syncer::SyncChangeList image_deletions, tracking_deletions;
 966   for (std::set<GURL>::const_iterator iter = favicon_urls.begin();
 967        iter != favicon_urls.end(); ++iter) {
 968     FaviconMap::iterator favicon_iter = synced_favicons_.find(*iter);
 969     if (favicon_iter == synced_favicons_.end())
 970       continue;
 971     DeleteSyncedFavicon(favicon_iter,
 972                         &image_deletions,
 973                         &tracking_deletions);
 974   }
 975   DVLOG(1) << "Deleting " << image_deletions.size() << " synced favicons.";
 976   if (favicon_images_sync_processor_.get()) {
 977     favicon_images_sync_processor_->ProcessSyncChanges(FROM_HERE,
 978                                                        image_deletions);
 979   }
 980   if (favicon_tracking_sync_processor_.get()) {
 981     favicon_tracking_sync_processor_->ProcessSyncChanges(FROM_HERE,
 982                                                          tracking_deletions);
 983   }
 984 }
 985
 986 void FaviconCache::DeleteSyncedFavicon(
 987     FaviconMap::iterator favicon_iter,
 988     syncer::SyncChangeList* image_changes,
 989     syncer::SyncChangeList* tracking_changes) {
 990   linked_ptr<SyncedFaviconInfo> favicon_info = favicon_iter->second;
 991   if (FaviconInfoHasImages(*(favicon_iter->second))) {
 992     DVLOG(1) << "Deleting image for "
 993              << favicon_iter->second.get()->favicon_url;
 994     image_changes->push_back(
 995         syncer::SyncChange(FROM_HERE,
 996                            syncer::SyncChange::ACTION_DELETE,
 997                            syncer::SyncData::CreateLocalDelete(
 998                                favicon_info->favicon_url.spec(),
 999                                syncer::FAVICON_IMAGES)));
1000   }
1001   if (FaviconInfoHasTracking(*(favicon_iter->second))) {
1002     DVLOG(1) << "Deleting tracking for "
1003              << favicon_iter->second.get()->favicon_url;
1004     tracking_changes->push_back(
1005         syncer::SyncChange(FROM_HERE,
1006                            syncer::SyncChange::ACTION_DELETE,
1007                            syncer::SyncData::CreateLocalDelete(
1008                                favicon_info->favicon_url.spec(),
1009                                syncer::FAVICON_TRACKING)));
1010   }
1011   DropSyncedFavicon(favicon_iter);
1012 }
1013
1014 void FaviconCache::DropSyncedFavicon(FaviconMap::iterator favicon_iter) {
1015   DVLOG(1) << "Dropping favicon " << favicon_iter->second.get()->favicon_url;
1016   recent_favicons_.erase(favicon_iter->second);
1017   synced_favicons_.erase(favicon_iter);
1018 }
1019
1020 void FaviconCache::DropPartialFavicon(FaviconMap::iterator favicon_iter,
1021                                       syncer::ModelType type) {
1022   // If the type being dropped has no valid data, do nothing.
1023   if ((type == syncer::FAVICON_TRACKING &&
1024        !FaviconInfoHasTracking(*favicon_iter->second)) ||
1025       (type == syncer::FAVICON_IMAGES &&
1026        !FaviconInfoHasImages(*favicon_iter->second))) {
1027     return;
1028   }
1029
1030   // If the type being dropped is the only type with valid data, just delete
1031   // the favicon altogether.
1032   if ((type == syncer::FAVICON_TRACKING &&
1033        !FaviconInfoHasImages(*favicon_iter->second)) ||
1034       (type == syncer::FAVICON_IMAGES &&
1035        !FaviconInfoHasTracking(*favicon_iter->second))) {
1036     DropSyncedFavicon(favicon_iter);
1037     return;
1038   }
1039
1040   if (type == syncer::FAVICON_IMAGES) {
1041     DVLOG(1) << "Dropping favicon image "
1042              << favicon_iter->second.get()->favicon_url;
1043     for (int i = 0; i < NUM_SIZES; ++i) {
1044       favicon_iter->second->bitmap_data[i] =
1045           favicon_base::FaviconRawBitmapResult();
1046     }
1047     DCHECK(!FaviconInfoHasImages(*favicon_iter->second));
1048   } else {
1049     DCHECK_EQ(type, syncer::FAVICON_TRACKING);
1050     DVLOG(1) << "Dropping favicon tracking "
1051              << favicon_iter->second.get()->favicon_url;
1052     recent_favicons_.erase(favicon_iter->second);
1053     favicon_iter->second->last_visit_time = base::Time();
1054     favicon_iter->second->is_bookmarked = false;
1055     recent_favicons_.insert(favicon_iter->second);
1056     DCHECK(!FaviconInfoHasTracking(*favicon_iter->second));
1057   }
1058 }
1059
1060 size_t FaviconCache::NumFaviconsForTest() const {
1061   return synced_favicons_.size();
1062 }
1063
1064 size_t FaviconCache::NumTasksForTest() const {
1065   return page_task_map_.size();
1066 }
1067
1068 }  // namespace browser_sync