Update touch selection to only modify one selection point at a time.

content/renderer/render_frame_impl.h

 // Copyright 2013 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.
 
 #ifndef CONTENT_RENDERER_RENDER_FRAME_IMPL_H_
 #define CONTENT_RENDERER_RENDER_FRAME_IMPL_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 523 matching lines @@
   void OnCustomContextMenuAction(const CustomContextMenuContext& custom_context,
                                  unsigned action);
   void OnUndo();
   void OnRedo();
   void OnCut();
   void OnCopy();
   void OnPaste();
   void OnPasteAndMatchStyle();
   void OnDelete();
   void OnSelectAll();
-  void OnSelectRange(const gfx::Point& start, const gfx::Point& end);
+  void OnSelectRange(const gfx::Point& base, const gfx::Point& extent);
   void OnUnselect();
+  void OnMoveRangeSelectionExtent(const gfx::Point& point);
   void OnReplace(const base::string16& text);
   void OnReplaceMisspelling(const base::string16& text);
   void OnCSSInsertRequest(const std::string& css);
   void OnJavaScriptExecuteRequest(const base::string16& javascript,
                                   int id,
                                   bool notify_result);
   void OnJavaScriptExecuteRequestForTests(const base::string16& javascript,
                                           int id,
                                           bool notify_result);
   void OnSetEditableSelectionOffsets(int start, int end);
@@ skipping 242 matching lines @@
 #endif
 
   base::WeakPtrFactory<RenderFrameImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderFrameImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_FRAME_IMPL_H_