cc: Add mailbox support to ResourceProvider write locks.

cc/tiles/tile_manager.h

Index: cc/tiles/tile_manager.h
diff --git a/cc/tiles/tile_manager.h b/cc/tiles/tile_manager.h
index 588bed8decfaa05cf5c1c92a0d15b2686ef5ff60..87a8e5c197693c09782b69367c608fa8fedf2416 100644
--- a/cc/tiles/tile_manager.h
+++ b/cc/tiles/tile_manager.h
@@ -120,6 +120,7 @@ class CC_EXPORT TileManager {
   void SetResources(ResourcePool* resource_pool,
                     ImageDecodeController* image_decode_controller,
                     TileTaskManager* tile_task_manager,
+                    RasterBufferProvider* raster_buffer_provider,
                     size_t scheduled_raster_task_limit,
                     bool use_gpu_rasterization);
 
@@ -148,8 +149,7 @@ class CC_EXPORT TileManager {
       TileDrawInfo& draw_info = tiles[i]->draw_info();
       draw_info.resource_ = resource_pool_->AcquireResource(
           tiles[i]->desired_texture_size(),
-          tile_task_manager_->GetRasterBufferProvider()->GetResourceFormat(
-              false));
+          raster_buffer_provider_->GetResourceFormat(false));
     }
   }
 
@@ -167,6 +167,9 @@ class CC_EXPORT TileManager {
 
   void SetTileTaskManagerForTesting(TileTaskManager* tile_task_manager);
 
+  void SetRasterBufferProviderForTesting(
+      RasterBufferProvider* raster_buffer_provider);
+
   void FreeResourcesAndCleanUpReleasedTilesForTesting() {
     FreeResourcesForReleasedTiles();
     CleanUpReleasedTiles();
@@ -294,6 +297,7 @@ class CC_EXPORT TileManager {
   base::SequencedTaskRunner* task_runner_;
   ResourcePool* resource_pool_;
   TileTaskManager* tile_task_manager_;
+  RasterBufferProvider* raster_buffer_provider_;
   GlobalStateThatImpactsTilePriority global_state_;
   size_t scheduled_raster_task_limit_;
   const bool use_partial_raster_;