Convert main-thread overscroll parameters into viewport space.

third_party/WebKit/Source/web/ChromeClientImpl.cpp

Index: third_party/WebKit/Source/web/ChromeClientImpl.cpp
diff --git a/third_party/WebKit/Source/web/ChromeClientImpl.cpp b/third_party/WebKit/Source/web/ChromeClientImpl.cpp
index 2210928659e4074606bc73b74029c8499211d3cc..f8530b504ebae095b1e7c60df3924c9635846b97 100644
--- a/third_party/WebKit/Source/web/ChromeClientImpl.cpp
+++ b/third_party/WebKit/Source/web/ChromeClientImpl.cpp
@@ -353,12 +353,12 @@ Page* ChromeClientImpl::createWindow(LocalFrame* frame, const FrameLoadRequest&
     return newView->page();
 }
 
-void ChromeClientImpl::didOverscroll(const FloatSize& unusedDelta, const FloatSize& accumulatedRootOverScroll, const FloatPoint& position, const FloatSize& velocity)
+void ChromeClientImpl::didOverscroll(const FloatSize& overscrollDelta, const FloatSize& accumulatedOverscroll, const FloatPoint& positionInViewport, const FloatSize& velocityInViewport)
 {
     if (!m_webView->client())
         return;
 
-    m_webView->client()->didOverscroll(unusedDelta, accumulatedRootOverScroll, position, velocity);
+    m_webView->client()->didOverscroll(overscrollDelta, accumulatedOverscroll, positionInViewport, velocityInViewport);
 }
 
 void ChromeClientImpl::show(NavigationPolicy navigationPolicy)