Don't create new tabs for middle clicks on bookmark items when the user releases off the item.

BUG=14518
TEST=see bug

Review URL: http://codereview.chromium.org/155902

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@21254 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/gtk/bookmark_bar_gtk.cc

@@ -558,6 +558,12 @@ gboolean BookmarkBarGtk::OnButtonReleased(GtkWidget* sender,
     return FALSE;
   }
 
+  // Don't take any action if the user releases outside the button.
+  if (event->x < 0 || event->y < 0 || event->x >= sender->allocation.width ||
+      event->y >= sender->allocation.height) {
+    return FALSE;
+  }
+
   const BookmarkNode* node = bar->GetNodeForToolButton(sender);
   DCHECK(node);
   DCHECK(bar->page_navigator_);