Add better support for RGBA_4444 textures.

cc/raster/one_copy_tile_task_worker_pool.cc

 // Copyright 2014 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 "cc/raster/one_copy_tile_task_worker_pool.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/strings/stringprintf.h"
@@ skipping 307 matching lines @@
     task->WillComplete();
     task->CompleteOnOriginThread(this);
     task->DidComplete();
 
     task->RunReplyOnOriginThread();
   }
   completed_tasks_.clear();
 }
 
 ResourceFormat OneCopyTileTaskWorkerPool::GetResourceFormat() const {
-  return resource_provider_->best_texture_format();
+  return resource_provider_->memory_efficient_texture_format();
 }
 
 bool OneCopyTileTaskWorkerPool::GetResourceRequiresSwizzle() const {
   return !PlatformColor::SameComponentOrder(GetResourceFormat());
 }
 
 scoped_ptr<RasterBuffer> OneCopyTileTaskWorkerPool::AcquireBufferForRaster(
     const Resource* resource,
     uint64_t resource_content_id,
     uint64_t previous_content_id) {
   // TODO(danakj): If resource_content_id != 0, we only need to copy/upload
   // the dirty rect.
-  DCHECK_EQ(resource->format(), resource_provider_->best_texture_format());
+  DCHECK_EQ(resource->format(),
+            resource_provider_->memory_efficient_texture_format());
   return make_scoped_ptr<RasterBuffer>(new RasterBufferImpl(
-      this, resource_provider_, resource_provider_->best_texture_format(),
-      resource, previous_content_id));
+      this, resource_provider_,
+      resource_provider_->memory_efficient_texture_format(), resource,
+      previous_content_id));
 }
 
 void OneCopyTileTaskWorkerPool::ReleaseBufferForRaster(
     scoped_ptr<RasterBuffer> buffer) {
   // Nothing to do here. RasterBufferImpl destructor cleans up after itself.
 }
 
 void OneCopyTileTaskWorkerPool::PlaybackAndCopyOnWorkerThread(
     const Resource* resource,
     const ResourceProvider::ScopedWriteLockGL* resource_lock,
@@ skipping 387 matching lines @@
 
   staging_state->SetInteger("staging_buffer_count",
                             static_cast<int>(buffers_.size()));
   staging_state->SetInteger("busy_count",
                             static_cast<int>(busy_buffers_.size()));
   staging_state->SetInteger("free_count",
                             static_cast<int>(free_buffers_.size()));
 }
 
 }  // namespace cc