Add missing web_contents.h include

chrome/browser/extensions/chrome_extension_test_notification_observer.cc

 // Copyright 2016 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/extensions/chrome_extension_test_notification_observer.h>
 #include "base/scoped_observer.h"
 #include "chrome/browser/extensions/extension_action_test_util.h"
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "content/public/browser/browser_context.h"
+#include "content/public/browser/web_contents.h"
 #include "extensions/browser/notification_types.h"
 #include "extensions/browser/process_manager.h"
 #include "extensions/common/extension.h"
 
 using extensions::Extension;
 
 namespace {
 
 // A callback that returns true if the condition has been met and takes no
 // arguments.
@@ skipping 92 matching lines @@
 
 void ChromeExtensionTestNotificationObserver::WaitForExtensionAndViewLoad() {
   WaitForExtensionLoad();
   WaitForExtensionViewsToLoad();
 }
 
 void ChromeExtensionTestNotificationObserver::OnPageActionsUpdated(
     content::WebContents* web_contents) {
   MaybeQuit();
 }