Implement basic theming for panel titlebars.

chrome/browser/ui/cocoa/chrome_browser_window.h

Index: chrome/browser/ui/cocoa/chrome_browser_window.h
diff --git a/chrome/browser/ui/cocoa/chrome_browser_window.h b/chrome/browser/ui/cocoa/chrome_browser_window.h
index 64c0123fb510226c8fb81f36503fd1d04ecfef23..fea57beab512c8edcaffd1b4494bd89ae7919996 100644
--- a/chrome/browser/ui/cocoa/chrome_browser_window.h
+++ b/chrome/browser/ui/cocoa/chrome_browser_window.h
@@ -8,12 +8,11 @@
 
 #import <Cocoa/Cocoa.h>
 
-#include "chrome/browser/ui/cocoa/chrome_event_processing_window.h"
+#include "chrome/browser/ui/cocoa/themed_browser_window.h"
 
 // Common base class for chrome browser windows.  Contains methods relating to
-// theming and hole punching that are shared between framed and fullscreen
-// windows.
-@interface ChromeBrowserWindow : ChromeEventProcessingWindow {
+// hole punching that are shared between framed and fullscreen windows.
+@interface ChromeBrowserWindow : ThemedBrowserWindow {
  @private
   int underlaySurfaceCount_;
 }