Add new views::LabelButton and LabelButtonBorder.

ui/views/controls/label.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_VIEWS_CONTROLS_LABEL_H_
 #define UI_VIEWS_CONTROLS_LABEL_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 56 matching lines @@
   // Sets the label text.
   void SetText(const string16& text);
 
   // Sets the label text to |email|.  Emails have a custom eliding algorithm.
   void SetEmail(const string16& email);
 
   // Returns the font used by this label.
   gfx::Font font() const { return font_; }
 
   // Returns the label text.
-  string16 text() const { return text_; };
+  const string16& text() const { return text_; };
 
   // Enables or disables auto-color-readability (enabled by default).  If this
   // is enabled, then calls to set any foreground or background color will
   // trigger an automatic mapper that uses color_utils::GetReadableColor() to
   // ensure that the foreground colors are readable over the background color.
   void SetAutoColorReadabilityEnabled(bool enabled);
 
   // Sets the color.  This will automatically force the color to be readable
   // over the current background color.
   virtual void SetEnabledColor(SkColor color);
@@ skipping 213 matching lines @@
 
   // Should a shadow be drawn behind the text?
   bool has_shadow_;
 
   DISALLOW_COPY_AND_ASSIGN(Label);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_LABEL_H_