Insert pinch zoom virtual viewport layers to graphics layer tree.

Source/WebKit/chromium/src/WebViewImpl.h

Index: Source/WebKit/chromium/src/WebViewImpl.h
diff --git a/Source/WebKit/chromium/src/WebViewImpl.h b/Source/WebKit/chromium/src/WebViewImpl.h
index 2c8b37643916a43dd36d3f48b2f8c57dcc7858c8..c09ec61711761bd4e48ed16803eacf5dbd2ffaf2 100644
--- a/Source/WebKit/chromium/src/WebViewImpl.h
+++ b/Source/WebKit/chromium/src/WebViewImpl.h
@@ -81,6 +81,7 @@ class PlatformKeyboardEvent;
 class PopupContainer;
 class PopupMenuClient;
 class Range;
+class RenderLayerCompositor;
 class RenderTheme;
 class TextFieldDecorator;
 class Widget;
@@ -94,6 +95,7 @@ class ContextMenuClientImpl;
 class DeviceOrientationClientProxy;
 class GeolocationClientProxy;
 class LinkHighlight;
+class PinchViewports;
 class PrerendererClientImpl;
 class SpeechInputClientImpl;
 class SpeechRecognitionClientProxy;
@@ -516,6 +518,7 @@ public:
     void scheduleCompositingLayerSync();
     void scrollRootLayerRect(const WebCore::IntSize& scrollDelta, const WebCore::IntRect& clipRect);
     WebCore::GraphicsLayerFactory* graphicsLayerFactory() const;
+    WebCore::RenderLayerCompositor* compositor() const;
     void registerForAnimations(WebLayer*);
     void scheduleAnimation();
 
@@ -839,6 +842,8 @@ private:
     bool m_showPaintRects;
     bool m_showDebugBorders;
     bool m_continuousPaintingEnabled;
+
+    OwnPtr<PinchViewports> m_pinchViewports;
 };
 
 } // namespace WebKit