Implement basic theming for panel titlebars.

chrome/browser/ui/cocoa/browser_window_cocoa.mm

Index: chrome/browser/ui/cocoa/browser_window_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/browser_window_cocoa.mm b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
index 9ad67b9fb8c781684f130528a948488e5681b892..16f5cd565e28ab51ac514469045342c8d78720dc 100644
--- a/chrome/browser/ui/cocoa/browser_window_cocoa.mm
+++ b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
@@ -203,24 +203,10 @@ void BrowserWindowCocoa::UpdateTitleBar() {
   NSString* newTitle =
       base::SysUTF16ToNSString(browser_->GetWindowTitleForCurrentTab());
 
-  // Work around Cocoa bug: if a window changes title during the tracking of the
-  // Window menu it doesn't display well and the constant re-sorting of the list
-  // makes it difficult for the user to pick the desired window. Delay window
-  // title updates until the default run-loop mode.
-
-  if (pending_window_title_.get())
-    [[NSRunLoop currentRunLoop]
-        cancelPerformSelector:@selector(setTitle:)
-                       target:window()
-                     argument:pending_window_title_.get()];
-
-  pending_window_title_.reset([newTitle copy]);
-  [[NSRunLoop currentRunLoop]
-      performSelector:@selector(setTitle:)
-               target:window()
-             argument:newTitle
-                order:0
-                modes:[NSArray arrayWithObject:NSDefaultRunLoopMode]];
+  pending_window_title_.reset(
+      [BrowserWindowUtils scheduleReplaceOldTitle:pending_window_title_.get()
+                                     withNewTitle:newTitle
+                                        forWindow:window()]);
 }
 
 void BrowserWindowCocoa::BookmarkBarStateChanged(