gfx::Image: Added thread checker.

chrome/browser/themes/browser_theme_pack.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/themes/browser_theme_pack.h"
 
 #include <limits.h>
 #include <stddef.h>
 
 #include <limits>
@@ skipping 519 matching lines @@
   const gfx::ImageSkia overlay_;
   const color_utils::HSL hsl_shift_;
   const int vertical_offset_;
 
   DISALLOW_COPY_AND_ASSIGN(TabBackgroundImageSource);
 };
 
 }  // namespace
 
 BrowserThemePack::~BrowserThemePack() {
+  DCHECK_CURRENTLY_ON(BrowserThread::FILE);
+
   if (!data_pack_.get()) {
     delete header_;
     delete [] tints_;
     delete [] colors_;
     delete [] display_properties_;
     delete [] source_images_;
   }
+
+  // |images_| will trigger the thread-checker as the images were built on the
+  // UI thread and we are on the FILE thread. As a special case, it is safe to
+  // delete them on the FILE thread because there are no remaining references to
+  // this BrowserThemePack from the UI thread. Explicitly detach all the images
+  // from the UI thread to suppress the error.
+  for (auto image : images_)
+    image.second.DetachFromThread();
+
+  // For the same reason, detach all of the |images_on_file_thread_| from
+  // whatever thread they are attached to. (Note that |images_on_file_thread_|
+  // is usually accessed on the FILE thread, but not always.)
+  for (auto image : images_on_file_thread_)
+    image.second.DetachFromThread();
 }
 
 // static
 void BrowserThemePack::BuildFromExtension(
     const extensions::Extension* extension,
     scoped_refptr<BrowserThemePack> pack) {
   DCHECK(extension);
   DCHECK(extension->is_theme());
   DCHECK(!pack->is_valid());
 
@@ skipping 30 matching lines @@
   // image if a caller of BrowserThemePack::GetImageNamed() requests an
   // ImageSkiaRep for a scale factor not specified by the theme author.
   // Callers of BrowserThemePack::GetImageNamed() to be able to retrieve
   // ImageSkiaReps for all supported scale factors.
   for (ImageCache::iterator it = pack->images_.begin();
        it != pack->images_.end(); ++it) {
     const gfx::ImageSkia source_image_skia = it->second.AsImageSkia();
     ThemeImageSource* source = new ThemeImageSource(source_image_skia);
     // image_skia takes ownership of source.
     gfx::ImageSkia image_skia(source, source_image_skia.size());
+    // From now on, it->second will only be stored in |images_on_file_thread_|,
+    // so detach it from the UI thread.
+    it->second.DetachFromThread();
     it->second = gfx::Image(image_skia);
   }
 
   // Generate raw images (for new-tab-page attribution and background) for
   // any missing scale from an available scale image.
   for (size_t i = 0; i < arraysize(kPreloadIDs); ++i) {
     pack->GenerateRawImageForAllSupportedScales(kPreloadIDs[i]);
   }
 
   // The BrowserThemePack is now in a consistent state.
@@ skipping 819 matching lines @@
                                            false,
                                            &bitmap_data)) {
       NOTREACHED() << "Unable to encode theme image for prs_id="
                    << prs_id << " for scale_factor=" << scale_factors_[i];
       break;
     }
     image_memory_[scaled_raw_id] =
         base::RefCountedBytes::TakeVector(&bitmap_data);
   }
 }