PlzNavigate: fix timing issue in app window creation

content/browser/web_contents/web_contents_impl.h

 // 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.
 
 #ifndef CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 #define CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 498 matching lines @@
       SiteInstance* instance) override;
   SessionStorageNamespaceMap GetSessionStorageNamespaceMap() override;
   FrameTree* GetFrameTree() override;
   void SetIsVirtualKeyboardRequested(bool requested) override;
   bool IsVirtualKeyboardRequested() override;
 
   // NavigatorDelegate ---------------------------------------------------------
 
   void DidStartNavigation(NavigationHandle* navigation_handle) override;
   void DidRedirectNavigation(NavigationHandle* navigation_handle) override;
+  void AboutToCommitNavigation(NavigationHandle* navigation_handle) override;
   void DidCommitNavigation(NavigationHandle* navigation_handle) override;
   void DidFinishNavigation(NavigationHandle* navigation_handle) override;
   void DidStartProvisionalLoad(RenderFrameHostImpl* render_frame_host,
                                const GURL& validated_url,
                                bool is_error_page,
                                bool is_iframe_srcdoc) override;
   void DidFailProvisionalLoadWithError(
       RenderFrameHostImpl* render_frame_host,
       const FrameHostMsg_DidFailProvisionalLoadWithError_Params& params)
       override;
@@ skipping 795 matching lines @@
   // Adds/removes a callback called on creation of each new WebContents.
   static void AddCreatedCallbackForTesting(const CreatedCallback& callback);
   static void RemoveCreatedCallbackForTesting(const CreatedCallback& callback);
 
   DISALLOW_COPY_AND_ASSIGN(FriendZone);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_