Fix MultiPictureDraw issues with GpuImageDecodeController

cc/playback/raster_source.h

 // 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.
 
 #ifndef CC_PLAYBACK_RASTER_SOURCE_H_
 #define CC_PLAYBACK_RASTER_SOURCE_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 98 matching lines @@
   virtual sk_sp<SkPicture> GetFlattenedPicture();
   virtual size_t GetPictureMemoryUsage() const;
 
   // Return true if LCD anti-aliasing may be used when rastering text.
   virtual bool CanUseLCDText() const;
 
   scoped_refptr<RasterSource> CreateCloneWithoutLCDText() const;
 
   // Image decode controller should be set once. Its lifetime has to exceed that
   // of the raster source, since the raster source will access it during raster.
-  void SetImageDecodeController(ImageDecodeController* image_decode_controller);
+  void set_image_decode_controller(
+      ImageDecodeController* image_decode_controller) {
+    DCHECK(image_decode_controller);
+    image_decode_controller_ = image_decode_controller;
+  }
+
+  // Returns the ImageDecodeController, currently only used by
+  // GpuRasterBufferProvider in order to create its own ImageHijackCanvas.
+  // Because of the MultiPictureDraw approach used by GPU raster, it does not
+  // integrate well with the use of the ImageHijackCanvas internal to this
+  // class. See gpu_raster_buffer_provider.cc for more information.
+  // TODO(crbug.com/628394): Redesign this to avoid exposing
+  // ImageDecodeController from the raster source.
+  ImageDecodeController* image_decode_controller() const {
+    return image_decode_controller_;
+  }
 
  protected:
   friend class base::RefCountedThreadSafe<RasterSource>;
 
   RasterSource(const RecordingSource* other, bool can_use_lcd_text);
   RasterSource(const RasterSource* other, bool can_use_lcd_text);
   virtual ~RasterSource();
 
   // These members are const as this raster source may be in use on another
   // thread and so should not be touched after construction.
@@ skipping 20 matching lines @@
   void RasterCommon(SkCanvas* canvas, SkPicture::AbortCallback* callback) const;
 
   void PrepareForPlaybackToCanvas(SkCanvas* canvas) const;
 
   DISALLOW_COPY_AND_ASSIGN(RasterSource);
 };
 
 }  // namespace cc
 
 #endif  // CC_PLAYBACK_RASTER_SOURCE_H_