Add a new resizer corner overlay.

chrome/browser/browser_window_cocoa.mm

Index: chrome/browser/browser_window_cocoa.mm
===================================================================
--- chrome/browser/browser_window_cocoa.mm	(revision 9328)
+++ chrome/browser/browser_window_cocoa.mm	(working copy)
@@ -77,10 +77,14 @@
   return bounds;
 }
 
-bool BrowserWindowCocoa::IsMaximized() {
+bool BrowserWindowCocoa::IsMaximized() const {
   return [window_ isZoomed];
 }
 
+gfx::Rect BrowserWindowCocoa::GetRootWindowResizerRect() const {
+  return gfx::Rect();
+}
+
 LocationBar* BrowserWindowCocoa::GetLocationBar() const {
   return NULL;
 }