Only show a beforeunload dialog if a frame has had a user gesture since its load.

content/public/test/browser_test_utils.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/public/test/browser_test_utils.h"
 
 #include <stddef.h>
 #include <tuple>
 #include <utility>
 
@@ skipping 453 matching lines @@
         Source<NavigationController>(&web_contents->GetController()));
     load_stop_observer.Wait();
   }
 }
 
 bool WaitForLoadStop(WebContents* web_contents) {
   WaitForLoadStopWithoutSuccessCheck(web_contents);
   return IsLastCommittedEntryOfPageType(web_contents, PAGE_TYPE_NORMAL);
 }
 
+void PrepContentsForBeforeUnloadTest(WebContents* web_contents) {
+  for (auto* frame : web_contents->GetAllFrames()) {
+    // JavaScript onbeforeunload dialogs are ignored unless the frame received a
+    // user gesture. Make sure the frames have user gestures.
+    frame->ExecuteJavaScriptWithUserGestureForTests(base::string16());
+
+    // Disable the hang monitor, otherwise there will be a race between the
+    // beforeunload dialog and the beforeunload hang timer.
+    frame->DisableBeforeUnloadHangMonitorForTesting();
+  }
+}
+
 bool IsLastCommittedEntryOfPageType(WebContents* web_contents,
                                     content::PageType page_type) {
   NavigationEntry* last_entry =
       web_contents->GetController().GetLastCommittedEntry();
   if (!last_entry)
     return false;
   return last_entry->GetPageType() == page_type;
 }
 
 void CrashTab(WebContents* web_contents) {
@@ skipping 1553 matching lines @@
                                  bool user_gesture,
                                  bool last_unlocked_by_target,
                                  bool privileged) {
   IPC::IpcSecurityTestUtil::PwnMessageReceived(
       process->GetChannel(),
       ViewHostMsg_LockMouse(routing_id, user_gesture, last_unlocked_by_target,
                             privileged));
 }
 
 }  // namespace content