Use Titlebar instead of TitleBar consistently in panels code.

chrome/browser/ui/panels/panel_browser_frame_view.h

 // Copyright (c) 2011 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 CHROME_BROWSER_UI_PANELS_PANEL_BROWSER_FRAME_VIEW_H_
 #define CHROME_BROWSER_UI_PANELS_PANEL_BROWSER_FRAME_VIEW_H_
 #pragma once
 
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 123 matching lines @@
     PanelBrowserFrameView* view_;
     bool is_mouse_within_;
 
     DISALLOW_COPY_AND_ASSIGN(MouseWatcher);
   };
 
   // Returns the thickness of the entire nonclient left, right, and bottom
   // borders, including both the window frame and any client edge.
   int NonClientBorderThickness() const;
 
-  // Update control styles to indicate if the title bar is active or not.
+  // Update control styles to indicate if the titlebar is active or not.
   void UpdateControlStyles(PaintState paint_state);
 
   // Custom draw the frame.
   void PaintFrameBorder(gfx::Canvas* canvas);
   void PaintClientEdge(gfx::Canvas* canvas);
 
   // Called by MouseWatcher to notify if the mouse enters or leaves the window.
   void OnMouseEnterOrLeaveWindow(bool mouse_entered);
 
   // Retrieves the drawing metrics based on the current painting state.
@@ skipping 35 matching lines @@
   scoped_ptr<MouseWatcher> mouse_watcher_;
   ui::SimpleMenuModel settings_menu_contents_;
   views::MenuModelAdapter settings_menu_adapter_;
   views::MenuItemView settings_menu_;
   scoped_ptr<ExtensionUninstallDialog> extension_uninstall_dialog_;
 
   DISALLOW_COPY_AND_ASSIGN(PanelBrowserFrameView);
 };
 
 #endif  // CHROME_BROWSER_UI_PANELS_PANEL_BROWSER_FRAME_VIEW_H_