Refactor RegisterViewportLayers to use a struct instead of 6 values

content/renderer/gpu/render_widget_compositor.h

 // Copyright (c) 2013 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 CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_H_
 #define CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_H_
 
 #include <stdint.h>
 
 #include "base/callback.h"
@@ skipping 127 matching lines @@
                                double duration_sec) override;
   bool HasPendingPageScaleAnimation() const override;
   void HeuristicsForGpuRasterizationUpdated(bool matches_heuristics) override;
   void SetNeedsBeginFrame() override;
   void DidStopFlinging() override;
   void LayoutAndPaintAsync(
       blink::WebLayoutAndPaintAsyncCallback* callback) override;
   void CompositeAndReadbackAsync(
       blink::WebCompositeAndReadbackAsyncCallback* callback) override;
   void SetDeferCommits(bool defer_commits) override;
+  // TODO(pdr): Refactor to use a struct like LayerTreeHost::ViewportLayers.
   void RegisterViewportLayers(
       const blink::WebLayer* overscrollElasticityLayer,
       const blink::WebLayer* pageScaleLayer,
       const blink::WebLayer* innerViewportContainerLayer,
       const blink::WebLayer* outerViewportContainerLayer,
       const blink::WebLayer* innerViewportScrollLayer,
       const blink::WebLayer* outerViewportScrollLayer) override;
   void ClearViewportLayers() override;
   void RegisterSelection(const blink::WebSelection& selection) override;
   void ClearSelection() override;
@@ skipping 88 matching lines @@
   cc::FrameSinkId frame_sink_id_;
 
   base::WeakPtrFactory<RenderWidgetCompositor> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetCompositor);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_H_