Insert pinch zoom virtual viewport layers to graphics layer tree.

Source/WebKit/chromium/src/WebSettingsImpl.cpp

Index: Source/WebKit/chromium/src/WebSettingsImpl.cpp
diff --git a/Source/WebKit/chromium/src/WebSettingsImpl.cpp b/Source/WebKit/chromium/src/WebSettingsImpl.cpp
index 2bc80914e7418b2278cfb94fd4a0f59b384fcb88..7d6618286a97b2655aa025dc90e785527d3efe21 100644
--- a/Source/WebKit/chromium/src/WebSettingsImpl.cpp
+++ b/Source/WebKit/chromium/src/WebSettingsImpl.cpp
@@ -60,6 +60,7 @@ WebSettingsImpl::WebSettingsImpl(Settings* settings)
     , m_deferredImageDecodingEnabled(false)
     , m_doubleTapToZoomEnabled(false)
     , m_supportDeprecatedTargetDensityDPI(false)
+    , m_pinchOverlayScrollbarThickness(0)
 {
     ASSERT(settings);
 }
@@ -683,6 +684,11 @@ void WebSettingsImpl::setSmartInsertDeleteEnabled(bool enabled)
     m_settings->setSmartInsertDeleteEnabled(enabled);
 }
 
+void WebSettingsImpl::setPinchOverlayScrollbarThickness(int thickness)
+{
+    m_pinchOverlayScrollbarThickness = thickness;
+}
+
 void WebSettingsImpl::setPinchVirtualViewportEnabled(bool enabled)
 {
     m_settings->setPinchVirtualViewportEnabled(enabled);