Re-land: cc: Add raster finished signals to RasterWorkerPool.

cc/test/fake_tile_manager.cc

Index: cc/test/fake_tile_manager.cc
diff --git a/cc/test/fake_tile_manager.cc b/cc/test/fake_tile_manager.cc
index 3410799c332ff259be6f51ff967272c17c6f5a6c..92b0fb872e2eff5defe55762cc88e7a484b19499 100644
--- a/cc/test/fake_tile_manager.cc
+++ b/cc/test/fake_tile_manager.cc
@@ -15,6 +15,8 @@ class FakeRasterWorkerPool : public RasterWorkerPool {
   FakeRasterWorkerPool() : RasterWorkerPool(NULL, 1) {}
 
   virtual void ScheduleTasks(RasterTask::Queue* queue) OVERRIDE {}
+  virtual void OnRasterTasksFinished() OVERRIDE {}
+  virtual void OnRasterTasksRequiredForActivationFinished() OVERRIDE {}
 };
 
 }  // namespace
@@ -37,4 +39,5 @@ FakeTileManager::FakeTileManager(TileManagerClient* client,
                   false,
                   NULL,
                   resource_provider->best_texture_format()) {}
-}
+
+}  // namespace cc