Add new API for only moving the selection extent point.

Source/web/WebRemoteFrameImpl.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "web/WebRemoteFrameImpl.h"
 
 #include "core/frame/FrameOwner.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/RemoteFrame.h"
@@ skipping 582 matching lines @@
 void WebRemoteFrameImpl::selectRange(const WebPoint& base, const WebPoint& extent)
 {
     ASSERT_NOT_REACHED();
 }
 
 void WebRemoteFrameImpl::selectRange(const WebRange&)
 {
     ASSERT_NOT_REACHED();
 }
 
+void WebRemoteFrameImpl::moveSelectionExtent(const WebPoint&)
+{
+    ASSERT_NOT_REACHED();
+}
+
 void WebRemoteFrameImpl::moveRangeSelection(const WebPoint& base, const WebPoint& extent)
 {
     ASSERT_NOT_REACHED();
 }
 
 void WebRemoteFrameImpl::moveCaretSelection(const WebPoint&)
 {
     ASSERT_NOT_REACHED();
 }
 
@@ skipping 248 matching lines @@
 void WebRemoteFrameImpl::initializeFromFrame(WebLocalFrame* source) const
 {
     ASSERT(source);
     WebLocalFrameImpl* localFrameImpl = toWebLocalFrameImpl(source);
     client()->initializeChildFrame(
         localFrameImpl->frame()->view()->frameRect(),
         localFrameImpl->frame()->view()->visibleContentScaleFactor());
 }
 
 } // namespace blink