[Extension UI Views] Add tests for clicking the different message bubble buttons

chrome/browser/ui/extensions/extension_message_bubble_factory.cc

 // Copyright 2015 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 "chrome/browser/ui/extensions/extension_message_bubble_factory.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/metrics/field_trial.h"
@@ skipping 155 matching lines @@
 
   controller.reset();
   return controller;
 }
 
 // static
 void ExtensionMessageBubbleFactory::set_override_for_tests(
     OverrideForTesting override) {
   g_override_for_testing = override;
 }
+
+// static
+bool ExtensionMessageBubbleFactory::is_enabled_for_testing() {
+  return g_override_for_testing == OVERRIDE_ENABLED;
+}