Implement basic theming for panel titlebars.

chrome/browser/ui/panels/panel_window_controller_cocoa.h

Index: chrome/browser/ui/panels/panel_window_controller_cocoa.h
diff --git a/chrome/browser/ui/panels/panel_window_controller_cocoa.h b/chrome/browser/ui/panels/panel_window_controller_cocoa.h
index 94df28d5650656d07b6fd555cb0caa9f7531de90..a37ed8df730bd152e44a40d4c0d429ad63f2719c 100644
--- a/chrome/browser/ui/panels/panel_window_controller_cocoa.h
+++ b/chrome/browser/ui/panels/panel_window_controller_cocoa.h
@@ -13,6 +13,7 @@
 
 #import "base/mac/cocoa_protocols.h"
 #include "base/memory/scoped_ptr.h"
+#import "chrome/browser/ui/cocoa/themed_window.h"
 
 @class FindBarCocoaController;
 class PanelBrowserWindowCocoa;
@@ -27,6 +28,10 @@ class PanelBrowserWindowCocoa;
 // Load the browser window nib and do any Cocoa-specific initialization.
 - (id)initWithBrowserWindow:(PanelBrowserWindowCocoa*)window;
 
+- (ui::ThemeProvider*)themeProvider;
+- (ThemedWindowStyle)themedWindowStyle;
+- (NSPoint)themePatternPhase;
+
 // Returns the TabContents' native view. It renders the content of the web page
 // in the Panel.
 - (NSView*)tabContentsView;