Hook up the resize rect for Mac and enable its use in the renderer (mac-only)...

chrome/browser/browser_window_controller.h

Index: chrome/browser/browser_window_controller.h
===================================================================
--- chrome/browser/browser_window_controller.h	(revision 10014)
+++ chrome/browser/browser_window_controller.h	(working copy)
@@ -55,6 +55,11 @@
 // Sets whether or not the current page in the frontmost tab is bookmarked.
 - (void)setStarredState:(BOOL)isStarred;
 
+// Return the rect, in WebKit coordinates (flipped), of the window's grow box
+// in the coordinate system of the content area of the currently selected tab.
+// |windowGrowBox| needs to be in the window's coordinate system.
+- (NSRect)selectedTabGrowBoxFromWindowGrowBox:(NSRect)windowGrowBox;
+
 @end
 
 #endif  // CHROME_BROWSER_BROWSER_WINDOW_CONTROLLER_H_