Add a unit tests for RenderText::FindCursorPosition.

ui/gfx/render_text_win.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_win.h"
 
 #include <algorithm>
 
 #include "base/i18n/break_iterator.h"
 #include "base/i18n/char_iterator.h"
@@ skipping 640 matching lines @@
         } else {
           pos = iter.pos() - iter.GetString().length();
         }
       }
     }
   }
   return SelectionModel(pos, CURSOR_FORWARD);
 }
 
 Range RenderTextWin::GetGlyphBounds(size_t index) {
+  EnsureLayout();
   const size_t run_index =
       GetRunContainingCaret(SelectionModel(index, CURSOR_FORWARD));
   // Return edge bounds if the index is invalid or beyond the layout text size.
   if (run_index >= runs_.size())
     return Range(string_width_);
   internal::TextRun* run = runs_[run_index];
   const size_t layout_index = TextIndexToLayoutIndex(index);
   return Range(GetGlyphXBoundary(run, layout_index, false),
                GetGlyphXBoundary(run, layout_index, true));
 }
@@ skipping 600 matching lines @@
   size_t position = LayoutIndexToTextIndex(run->range.end());
   position = IndexOfAdjacentGrapheme(position, CURSOR_BACKWARD);
   return SelectionModel(position, CURSOR_FORWARD);
 }
 
 RenderText* RenderText::CreateInstance() {
   return new RenderTextWin;
 }
 
 }  // namespace gfx