[Mac] Keep the page-info-bubble controller alive until done with layout.

chrome/browser/ui/cocoa/page_info_bubble_controller.mm

Index: chrome/browser/ui/cocoa/page_info_bubble_controller.mm
diff --git a/chrome/browser/ui/cocoa/page_info_bubble_controller.mm b/chrome/browser/ui/cocoa/page_info_bubble_controller.mm
index f9952d41bca4bea98bb482ff7902389f505abcc5..dd288ba8557296cee3c924f0f1300485ff0d11d0 100644
--- a/chrome/browser/ui/cocoa/page_info_bubble_controller.mm
+++ b/chrome/browser/ui/cocoa/page_info_bubble_controller.mm
@@ -131,6 +131,10 @@ class PageInfoModelBubbleBridge : public PageInfoModelObserver {
 
  private:
   void PerformLayout() {
+    // If the window is animating closed when this is called, the
+    // animation could be holding the last reference to |controller_|
+    // (and thus |this|).  Pin it until the task is completed.
+    scoped_nsobject<PageInfoBubbleController> keep_alive([controller_ retain]);
     [controller_ performLayout];
   }