Implement signin using webview

extensions/browser/guest_view/guest_view_base.cc

 // Copyright 2014 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 "extensions/browser/guest_view/guest_view_base.h"
 
 #include "base/lazy_instance.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
@@ skipping 57 matching lines @@
   ~EmbedderLifetimeObserver() override {}
 
   // WebContentsObserver implementation.
   void WebContentsDestroyed() override {
     // If the embedder is destroyed then destroy the guest.
     Destroy();
   }
 
   void AboutToNavigateRenderView(
       content::RenderViewHost* render_view_host) override {
+    if (destroyed_)
+      return;
+
+    guest_->WillDetachFromEmbedder();
     // If the embedder navigates then destroy the guest.
     Destroy();
   }
 
   void RenderProcessGone(base::TerminationStatus status) override {
     // If the embedder crashes, then destroy the guest.
     Destroy();
   }
 
  private:
@@ skipping 405 matching lines @@
 
 // static
 void GuestViewBase::RegisterGuestViewTypes() {
   AppViewGuest::Register();
   ExtensionOptionsGuest::Register();
   MimeHandlerViewGuest::Register();
   WebViewGuest::Register();
 }
 
 }  // namespace extensions