Made double-tap zoom work in pinch virtual viewport mode (Chromium-side).

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 "base/callback.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
@@ skipping 114 matching lines @@
   virtual void setShowDebugBorders(bool show);
   virtual void setContinuousPaintingEnabled(bool enabled);
   virtual void setShowScrollBottleneckRects(bool show);
   virtual void setTopControlsContentOffset(float);
 
   // cc::LayerTreeHostClient implementation.
   virtual void WillBeginMainFrame(int frame_id) OVERRIDE;
   virtual void DidBeginMainFrame() OVERRIDE;
   virtual void BeginMainFrame(const cc::BeginFrameArgs& args) OVERRIDE;
   virtual void Layout() OVERRIDE;
+  virtual void ApplyViewportDeltas(const gfx::Vector2d& inner_delta,
+                                   const gfx::Vector2d& outer_delta,
+                                   float page_scale,
+                                   float top_controls_delta) OVERRIDE;
   virtual void ApplyViewportDeltas(const gfx::Vector2d& scroll_delta,
                                    float page_scale,
                                    float top_controls_delta) OVERRIDE;
   virtual scoped_ptr<cc::OutputSurface> CreateOutputSurface(bool fallback)
       OVERRIDE;
   virtual void DidInitializeOutputSurface() OVERRIDE;
   virtual void WillCommit() OVERRIDE;
   virtual void DidCommit() OVERRIDE;
   virtual void DidCommitAndDrawFrame() OVERRIDE;
   virtual void DidCompleteSwapBuffers() OVERRIDE;
@@ skipping 15 matching lines @@
 
   bool send_v8_idle_notification_after_commit_;
   base::TimeTicks begin_main_frame_time_;
   // The time interval between BeginMainFrame calls, provided by the scheduler.
   base::TimeDelta begin_main_frame_interval_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_H_