Insert pinch zoom virtual viewport layers to graphics layer tree.

Source/WebKit/chromium/src/WebSettingsImpl.h

Index: Source/WebKit/chromium/src/WebSettingsImpl.h
diff --git a/Source/WebKit/chromium/src/WebSettingsImpl.h b/Source/WebKit/chromium/src/WebSettingsImpl.h
index cd9acde491bec1c2e02ab69a1d19f7b43c8cce6f..5d77930ca7c66e04b1917eda28b183dcf2ecadff 100644
--- a/Source/WebKit/chromium/src/WebSettingsImpl.h
+++ b/Source/WebKit/chromium/src/WebSettingsImpl.h
@@ -126,6 +126,7 @@ public:
     virtual void setPasswordEchoEnabled(bool);
     virtual void setPerTilePaintingEnabled(bool);
     virtual void setPictographFontFamily(const WebString&, UScriptCode = USCRIPT_COMMON);
+    virtual void setPinchOverlayScrollbarThickness(int);
     virtual void setPinchVirtualViewportEnabled(bool);
     virtual void setPluginsEnabled(bool);
     virtual void setPrivilegedWebGLExtensionsEnabled(bool);
@@ -176,6 +177,7 @@ public:
     bool doubleTapToZoomEnabled() const { return m_doubleTapToZoomEnabled; }
     bool perTilePaintingEnabled() const { return m_perTilePaintingEnabled; }
     bool supportDeprecatedTargetDensityDPI() const { return m_supportDeprecatedTargetDensityDPI; }
+    int pinchOverlayScrollbarThickness() const { return m_pinchOverlayScrollbarThickness; }
 
 private:
     WebCore::Settings* m_settings;
@@ -189,6 +191,7 @@ private:
     bool m_doubleTapToZoomEnabled;
     bool m_perTilePaintingEnabled;
     bool m_supportDeprecatedTargetDensityDPI;
+    int m_pinchOverlayScrollbarThickness;
 };
 
 } // namespace WebKit