Selectively disable rubber banding on mac.

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index 8836341267581ea88fede135a0af516a7b3bfb95..e40b087dc3e4b28bfdad49e634bfc7544925bd63 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -547,10 +547,10 @@ void WebViewImpl::handleMouseUp(LocalFrame& mainFrame, const WebMouseEvent& even
 #endif
 }
 
-bool WebViewImpl::handleMouseWheel(LocalFrame& mainFrame, const WebMouseWheelEvent& event)
+bool WebViewImpl::handleMouseWheel(LocalFrame& mainFrame, const WebMouseWheelEvent& event, bool canRubberbandLeft, bool canRubberbandRight)
 {
     hidePopups();
-    return PageWidgetEventHandler::handleMouseWheel(mainFrame, event);
+    return PageWidgetEventHandler::handleMouseWheel(mainFrame, event, canRubberbandLeft, canRubberbandRight);
 }
 
 void WebViewImpl::scrollBy(const WebFloatSize& delta)
@@ -571,7 +571,7 @@ void WebViewImpl::scrollBy(const WebFloatSize& delta)
         syntheticWheel.modifiers = m_flingModifier;
 
         if (m_page && m_page->mainFrame() && m_page->mainFrame()->view())
-            handleMouseWheel(*m_page->mainFrame(), syntheticWheel);
+            handleMouseWheel(*m_page->mainFrame(), syntheticWheel, false, false);
     } else {
         WebGestureEvent syntheticGestureEvent;
 
@@ -1752,6 +1752,10 @@ const WebInputEvent* WebViewImpl::m_currentInputEvent = 0;
 
 bool WebViewImpl::handleInputEvent(const WebInputEvent& inputEvent)
 {
+    return handleInputEvent(inputEvent, true, true);
+}
+bool WebViewImpl::handleInputEvent(const WebInputEvent& inputEvent, bool canRubberbandLeft, bool canRubberbandRight)
+{
     TRACE_EVENT0("input", "WebViewImpl::handleInputEvent");
     // If we've started a drag and drop operation, ignore input events until
     // we're done.
@@ -1805,7 +1809,7 @@ bool WebViewImpl::handleInputEvent(const WebInputEvent& inputEvent)
         return true;
     }
 
-    return PageWidgetDelegate::handleInputEvent(m_page.get(), *this, inputEvent);
+    return PageWidgetDelegate::handleInputEvent(m_page.get(), *this, inputEvent, canRubberbandLeft, canRubberbandRight);
 }
 
 void WebViewImpl::setCursorVisibilityState(bool isVisible)