Fix cursor positioning regression from r201136. GetCursorPos() shouldn't assume

ui/gfx/render_text_mac.cc

 // Copyright (c) 2012 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 "ui/gfx/render_text_mac.h"
 
 #include <ApplicationServices/ApplicationServices.h>
 
 #include <cmath>
 #include <utility>
@@ skipping 50 matching lines @@
   return SelectionModel();
 }
 
 SelectionModel RenderTextMac::AdjacentWordSelectionModel(
     const SelectionModel& selection,
     VisualCursorDirection direction) {
   // TODO(asvitkine): Implement this. http://crbug.com/131618
   return SelectionModel();
 }
 
-void RenderTextMac::GetGlyphBounds(size_t index,
-                                   ui::Range* xspan,
-                                   int* height) {
+ui::Range RenderTextMac::GetGlyphBounds(size_t index) {
   // TODO(asvitkine): Implement this. http://crbug.com/131618
+  return ui::Range();
 }
 
 std::vector<Rect> RenderTextMac::GetSubstringBounds(const ui::Range& range) {
   // TODO(asvitkine): Implement this. http://crbug.com/131618
   return std::vector<Rect>();
 }
 
 size_t RenderTextMac::TextIndexToLayoutIndex(size_t index) const {
   // TODO(asvitkine): Implement this. http://crbug.com/131618
   return index;
@@ skipping 236 matching lines @@
     run_origin.offset(run_width, 0);
   }
   runs_valid_ = true;
 }
 
 RenderText* RenderText::CreateInstance() {
   return new RenderTextMac;
 }
 
 }  // namespace gfx