SetNeedsRedraw directly when updating a visible tile.

cc/layers/picture_layer.h

 // Copyright 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.
 
 #ifndef CC_LAYERS_PICTURE_LAYER_H_
 #define CC_LAYERS_PICTURE_LAYER_H_
 
 #include "cc/base/invalidation_region.h"
 #include "cc/debug/devtools_instrumentation.h"
 #include "cc/debug/micro_benchmark_controller.h"
@@ skipping 27 matching lines @@
   void RunMicroBenchmark(MicroBenchmark* benchmark) override;
 
   ContentLayerClient* client() { return client_; }
 
   RecordingSource* GetRecordingSourceForTesting() {
     return recording_source_.get();
   }
 
  protected:
   explicit PictureLayer(ContentLayerClient* client);
+  // Allow tests to inject a recording source.
+  PictureLayer(ContentLayerClient* client, scoped_ptr<RecordingSource> source);
   ~PictureLayer() override;
 
   bool HasDrawableContent() const override;
   void UpdateCanUseLCDText();
 
  private:
   ContentLayerClient* client_;
   scoped_ptr<RecordingSource> recording_source_;
   devtools_instrumentation::
       ScopedLayerObjectTracker instrumentation_object_tracker_;
   // Invalidation to use the next time update is called.
   InvalidationRegion pending_invalidation_;
   // Invalidation from the last time update was called.
   Region recording_invalidation_;
   gfx::Rect last_updated_visible_content_rect_;
 
   int update_source_frame_number_;
   bool can_use_lcd_text_last_frame_;
 
   DISALLOW_COPY_AND_ASSIGN(PictureLayer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_PICTURE_LAYER_H_