Tests for dragging between two frames (potentially cross-site from main frame).

content/public/test/browser_test_utils.cc

Index: content/public/test/browser_test_utils.cc
diff --git a/content/public/test/browser_test_utils.cc b/content/public/test/browser_test_utils.cc
index 139301fa6344bb2f3106253aaed144e11cdb2a7e..988f637f37b8a6b9c9d76e98f8bab62b2d1b9af6 100644
--- a/content/public/test/browser_test_utils.cc
+++ b/content/public/test/browser_test_utils.cc
@@ -1303,7 +1303,8 @@ void DOMMessageQueue::RenderProcessGone(base::TerminationStatus status) {
     case base::TERMINATION_STATUS_STILL_RUNNING:
       break;
     default:
-      message_loop_runner_->Quit();
+      if (message_loop_runner_.get())
+        message_loop_runner_->Quit();
       break;
   }
 }