Mozart: Improve internal scene graph representation.

services/gfx/compositor/render/render_image.h

 // Copyright 2015 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 SERVICES_GFX_COMPOSITOR_RENDER_RENDER_IMAGE_H_
 #define SERVICES_GFX_COMPOSITOR_RENDER_RENDER_IMAGE_H_
 
 #include <memory>
 
 #include <GLES2/gl2.h>
@@ skipping 33 matching lines @@
       const GLbyte mailbox_name[GL_MAILBOX_SIZE_CHROMIUM],
       GLuint sync_point,
       uint32_t width,
       uint32_t height,
       const scoped_refptr<base::TaskRunner>& task_runner,
       const base::Closure& release_task);
 
   uint32_t width() const { return image_->width(); }
   uint32_t height() const { return image_->height(); }
 
-  // Gets the underlying image to rasterize.
+  // Gets the underlying image to rasterize, never null.
   const skia::RefPtr<SkImage>& image() const { return image_; }
 
  private:
   skia::RefPtr<SkImage> image_;
   std::shared_ptr<Releaser> releaser_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderImage);
 };
 
 }  // namespace compositor
 
 #endif  // SERVICES_GFX_COMPOSITOR_RENDER_RENDER_IMAGE_H_