Unpack theme data from extensions off of UI thread.

chrome/browser/themes/browser_theme_pack.cc

Index: chrome/browser/themes/browser_theme_pack.cc
diff --git a/chrome/browser/themes/browser_theme_pack.cc b/chrome/browser/themes/browser_theme_pack.cc
index a352c67826141a741a3250a9ad50002f8f22b15d..4f3da00892f7a834b1cd3985999ea460ed09c584 100644
--- a/chrome/browser/themes/browser_theme_pack.cc
+++ b/chrome/browser/themes/browser_theme_pack.cc
@@ -546,13 +546,13 @@ BrowserThemePack::~BrowserThemePack() {
 }
 
 // static
-scoped_refptr<BrowserThemePack> BrowserThemePack::BuildFromExtension(
-    const Extension* extension) {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+void BrowserThemePack::BuildFromExtension(
+    const extensions::Extension* extension,
+    scoped_refptr<BrowserThemePack> pack) {
   DCHECK(extension);
   DCHECK(extension->is_theme());
+  DCHECK(!pack->is_valid());
 
-  scoped_refptr<BrowserThemePack> pack(new BrowserThemePack);
   pack->BuildHeader(extension);
   pack->BuildTintsFromJSON(extensions::ThemeInfo::GetTints(extension));
   pack->BuildColorsFromJSON(extensions::ThemeInfo::GetColors(extension));
@@ -567,14 +567,14 @@ scoped_refptr<BrowserThemePack> BrowserThemePack::BuildFromExtension(
       &file_paths);
   pack->BuildSourceImagesArray(file_paths);
 
-  if (!pack->LoadRawBitmapsTo(file_paths, &pack->images_on_ui_thread_))
-    return NULL;
+  if (!pack->LoadRawBitmapsTo(file_paths, &pack->images_))
+    return;
 
-  pack->CreateImages(&pack->images_on_ui_thread_);
+  pack->CreateImages(&pack->images_);
 
   // Make sure the |images_on_file_thread_| has bitmaps for supported
   // scale factors before passing to FILE thread.
-  pack->images_on_file_thread_ = pack->images_on_ui_thread_;
+  pack->images_on_file_thread_ = pack->images_;
   for (ImageCache::iterator it = pack->images_on_file_thread_.begin();
        it != pack->images_on_file_thread_.end(); ++it) {
     gfx::ImageSkia* image_skia =
@@ -582,13 +582,13 @@ scoped_refptr<BrowserThemePack> BrowserThemePack::BuildFromExtension(
     image_skia->MakeThreadSafe();
   }
 
-  // Set ThemeImageSource on |images_on_ui_thread_| to resample the source
+  // Set ThemeImageSource on |images_| to resample the source
   // 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_on_ui_thread_.begin();
-       it != pack->images_on_ui_thread_.end(); ++it) {
+  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.
@@ -603,7 +603,7 @@ scoped_refptr<BrowserThemePack> BrowserThemePack::BuildFromExtension(
   }
 
   // The BrowserThemePack is now in a consistent state.
-  return pack;
+  pack->is_valid_ = true;
 }
 
 // static
@@ -671,6 +671,7 @@ scoped_refptr<BrowserThemePack> BrowserThemePack::BuildFromDataPack(
                 << "from those supported by platform.";
     return NULL;
   }
+  pack->is_valid_ = true;
   return pack;
 }
 
@@ -683,6 +684,13 @@ bool BrowserThemePack::IsPersistentImageID(int id) {
   return false;
 }
 
+BrowserThemePack::BrowserThemePack() : CustomThemeSupplier(EXTENSION) {
+  scale_factors_ = ui::GetSupportedScaleFactors();
+  // On Windows HiDPI SCALE_FACTOR_100P may not be supported by default.
+  if (!base::ContainsValue(scale_factors_, ui::SCALE_FACTOR_100P))
+    scale_factors_.push_back(ui::SCALE_FACTOR_100P);
+}
+
 bool BrowserThemePack::WriteToDisk(const base::FilePath& path) const {
   // Add resources for each of the property arrays.
   RawDataForWriting resources;
@@ -771,8 +779,8 @@ gfx::Image BrowserThemePack::GetImageNamed(int idr_id) {
     return gfx::Image();
 
   // Check if the image is cached.
-  ImageCache::const_iterator image_iter = images_on_ui_thread_.find(prs_id);
-  if (image_iter != images_on_ui_thread_.end())
+  ImageCache::const_iterator image_iter = images_.find(prs_id);
+  if (image_iter != images_.end())
     return image_iter->second;
 
   ThemeImagePngSource::PngMap png_map;
@@ -786,7 +794,7 @@ gfx::Image BrowserThemePack::GetImageNamed(int idr_id) {
     gfx::ImageSkia image_skia(new ThemeImagePngSource(png_map), 1.0f);
     // |image_skia| takes ownership of ThemeImagePngSource.
     gfx::Image ret = gfx::Image(image_skia);
-    images_on_ui_thread_[prs_id] = ret;
+    images_[prs_id] = ret;
     return ret;
   }
 
@@ -830,19 +838,6 @@ bool BrowserThemePack::HasCustomImage(int idr_id) const {
 
 // private:
 
-BrowserThemePack::BrowserThemePack()
-    : CustomThemeSupplier(EXTENSION),
-      header_(NULL),
-      tints_(NULL),
-      colors_(NULL),
-      display_properties_(NULL),
-      source_images_(NULL) {
-  scale_factors_ = ui::GetSupportedScaleFactors();
-  // On Windows HiDPI SCALE_FACTOR_100P may not be supported by default.
-  if (!base::ContainsValue(scale_factors_, ui::SCALE_FACTOR_100P))
-    scale_factors_.push_back(ui::SCALE_FACTOR_100P);
-}
-
 void BrowserThemePack::BuildHeader(const Extension* extension) {
   header_ = new BrowserThemePackHeader;
   header_->version = kThemePackVersion;