Move GetDocument method from WebFrame to WebLocalFrame.

third_party/WebKit/Source/core/exported/WebRemoteFrameImpl.cpp

Index: third_party/WebKit/Source/core/exported/WebRemoteFrameImpl.cpp
diff --git a/third_party/WebKit/Source/core/exported/WebRemoteFrameImpl.cpp b/third_party/WebKit/Source/core/exported/WebRemoteFrameImpl.cpp
index bb30a26fa24d644d544e7a93b5eb450a8cd60c5e..67e4ba20c5533d9fae797c759ddbf77cef1788aa 100644
--- a/third_party/WebKit/Source/core/exported/WebRemoteFrameImpl.cpp
+++ b/third_party/WebKit/Source/core/exported/WebRemoteFrameImpl.cpp
@@ -122,12 +122,6 @@ WebView* WebRemoteFrameImpl::View() const {
   return GetFrame()->GetPage()->GetChromeClient().GetWebView();
 }
 
-WebDocument WebRemoteFrameImpl::GetDocument() const {
-  // TODO(dcheng): this should also ASSERT_NOT_REACHED, but a lot of
-  // code tries to access the document of a remote frame at the moment.
-  return WebDocument();
-}
-
 WebPerformance WebRemoteFrameImpl::Performance() const {
   NOTREACHED();
   return WebPerformance();