Fix candidate window position issue.

ui/base/ime/text_input_client.h

 // 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.
 
 #ifndef UI_BASE_IME_TEXT_INPUT_CLIENT_H_
 #define UI_BASE_IME_TEXT_INPUT_CLIENT_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/i18n/rtl.h"
@@ skipping 60 matching lines @@
   // 1) Modify NativeTextfieldViews so it returns screen coordinates.
   // 2) Remove view-to-screen coordinates conversion code in InputMethodBridge.
   // 3) Modify InputMethodWin. It requires a rect in toplevel window's
   //    coordinates instead of screen.
   virtual gfx::Rect GetCaretBounds() = 0;
 
   // Retrieves the composition character boundary rectangle relative to the
   // screen coordinates. The |index| is zero-based index of character position
   // in composition text.
   // Returns false if there is no composition text or |index| is out of range.
+  // The |rect| is not touched in the case of failure.
   virtual bool GetCompositionCharacterBounds(uint32 index, gfx::Rect* rect) = 0;
 
   // Returns true if there is composition text.
   virtual bool HasCompositionText() = 0;
 
   // Document content operations ----------------------------------------------
 
   // Retrieves the UTF-16 based character range containing accessibled text in
   // the View. It must cover the composition and selection range.
   // Returns false if the information cannot be retrieved right now.
@@ skipping 34 matching lines @@
   // alignment of the current text box. It’s for supporting ctrl-shift on
   // Windows.
   // Returns false if the operation is not supported.
   virtual bool ChangeTextDirectionAndLayoutAlignment(
       base::i18n::TextDirection direction) = 0;
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_IME_TEXT_INPUT_CLIENT_H_