Add a NavigationThrottle to the public content/ interface

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 495 matching lines @@
   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 DidCommitNavigation(NavigationHandle* navigation_handle) override;
   void DidFinishNavigation(NavigationHandle* navigation_handle) override;
+  void AddNavigationThrottles(NavigationHandle* navigation_handle) override;

[nasko, 2015/08/31 23:25:15]

Might be worthwhile adding a "for_main_frame_only" type parameter. Most features
might not care about subframe navigations, so we shouldn't be installing their
throttles for subframes.

[clamy, 2015/09/03 15:30:52]

I'm not sure the parameter is necessary, since the NavigationHandle is provided
which has a method returning whether the navigation happens in a main frame. In
fact, the example here is using it precisely to register throttles only on main
frame navigations.

[nasko, 2015/09/04 23:36:49]

Acknowledged.

   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;
   void DidFailLoadWithError(RenderFrameHostImpl* render_frame_host,
                             const GURL& url,
@@ skipping 781 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_