Fix a deleted memory read with the infobars

chrome/browser/tab_contents/tab_contents.cc

Index: chrome/browser/tab_contents/tab_contents.cc
===================================================================
--- chrome/browser/tab_contents/tab_contents.cc	(revision 16872)
+++ chrome/browser/tab_contents/tab_contents.cc	(working copy)
@@ -313,21 +313,25 @@
       window->CloseConstrainedWindow();
   }
 
+  // Notify any observer that have a reference on this tab contents.
+  NotificationService::current()->Notify(
+      NotificationType::TAB_CONTENTS_DESTROYED,
+      Source<TabContents>(this),
+      NotificationService::NoDetails());
+
   // Notify any lasting InfobarDelegates that have not yet been removed that
   // whatever infobar they were handling in this TabContents has closed,
   // because the TabContents is going away entirely.
+  // This must happen after the TAB_CONTENTS_DESTROYED notification as the
+  // notification may trigger infobars calls that access their delegate. (and
+  // some implementations of InfoBarDelegate do delete themselves on
+  // InfoBarClosed()).
   for (int i = 0; i < infobar_delegate_count(); ++i) {
     InfoBarDelegate* delegate = GetInfoBarDelegateAt(i);
     delegate->InfoBarClosed();
   }
   infobar_delegates_.clear();
 
-  // Notify any observer that have a reference on this tab contents.
-  NotificationService::current()->Notify(
-      NotificationType::TAB_CONTENTS_DESTROYED,
-      Source<TabContents>(this),
-      NotificationService::NoDetails());
-
   // TODO(brettw) this should be moved to the view.
 #if defined(OS_WIN)
   // If we still have a window handle, destroy it. GetNativeView can return