Support auto-reload on errors.

chrome/renderer/net/net_error_helper.h

 // Copyright (c) 2013 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 CHROME_RENDERER_NET_NET_ERROR_HELPER_H_
 #define CHROME_RENDERER_NET_NET_ERROR_HELPER_H_
 
 #include <string>
 
 #include "chrome/common/net/net_error_info.h"
 #include "chrome/renderer/net/net_error_helper_core.h"
 #include "content/public/renderer/render_frame_observer.h"
 #include "content/public/renderer/render_frame_observer_tracker.h"
+#include "content/public/renderer/render_process_observer.h"
 
 class GURL;
+class MockableOneShotTimer;
 
 namespace content {
 class ResourceFetcher;
 }
 
 namespace blink {
 class WebFrame;
 class WebURLResponse;
 struct WebURLError;
 }
 
 // Listens for NetErrorInfo messages from the NetErrorTabHelper on the
 // browser side and updates the error page with more details (currently, just
 // DNS probe results) if/when available.
 class NetErrorHelper
     : public content::RenderFrameObserver,
       public content::RenderFrameObserverTracker<NetErrorHelper>,
+      public content::RenderProcessObserver,
       public NetErrorHelperCore::Delegate {
  public:
-  explicit NetErrorHelper(content::RenderFrame* render_view);
+  explicit NetErrorHelper(content::RenderFrame* render_view,
+                          bool auto_reload_enabled);

[Randy Smith (Not in Mondays), 2014/02/26 00:07:38]

I had a series of questions on how auto_reload_enabled is plumbed into
NetErrorHelper core that you never responded to, and that (at least based on
this comment) it looks like you didn't evaluate.  I think they were:

* Why pass it into NetErrorHelper instead of NEH getting it direct from the
command line?  I don't believe we have any NEH level tests, so this is just
extra verbiage in the API.

* Why use a setter on NEHC rather than pass it in in the constructor?

* Why not make NEHC a RenderProcessObserver instead of mapping that through NEH?
 I don't think it decreases testability any, and it decreases code cruft. 
(Check this with Matt, and if he doesn't like it, he wins.)

[Elly Fong-Jones, 2014/03/03 19:31:07]

Done.
That way it's toggle-able by individual tests after the NEHC constructor is
already run.
I talked to Matt and he nacked this. In particular, NEHC is intended to have
*no* external dependencies; making it a RenderProcessObserver entails
constructing a mock RenderProcess for it to observe when unit-testing it.

Now that you mention it, I don't see how NetErrorHelper actually gets attached
as an observer of the RenderThread...

   virtual ~NetErrorHelper();
 
   // RenderFrameObserver implementation.
   virtual void DidStartProvisionalLoad() OVERRIDE;
   virtual void DidCommitProvisionalLoad(bool is_new_navigation) OVERRIDE;
   virtual void DidFinishLoad() OVERRIDE;
   virtual void OnStop() OVERRIDE;
 
   // IPC::Listener implementation.
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
+  // RenderProcessObserver implementation.
+  virtual void NetworkStateChanged(bool online) OVERRIDE;
+
   // Examines |frame| and |error| to see if this is an error worthy of a DNS
   // probe.  If it is, initializes |error_strings| based on |error|,
   // |is_failed_post|, and |locale| with suitable strings and returns true.
   // If not, returns false, in which case the caller should look up error
   // strings directly using LocalizedError::GetNavigationErrorStrings.
   //
   // Updates the NetErrorHelper with the assumption the page will be loaded
   // immediately.
   void GetErrorHTML(blink::WebFrame* frame,
                     const blink::WebURLError& error,
                     bool is_failed_post,
                     std::string* error_html);
 
+  // Returns whether a load for |url| should have its error page suppressed.
+  bool ShouldSuppressErrorPage(const GURL& url);
+
  private:
   // NetErrorHelperCore::Delegate implementation:
   virtual void GenerateLocalizedErrorPage(const blink::WebURLError& error,
                                           bool is_failed_post,
                                           std::string* html) const OVERRIDE;
   virtual void LoadErrorPageInMainFrame(const std::string& html,
                                         const GURL& failed_url) OVERRIDE;
   virtual void UpdateErrorPage(const blink::WebURLError& error,
                                bool is_failed_post) OVERRIDE;
   virtual void FetchErrorPage(const GURL& url) OVERRIDE;
   virtual void CancelFetchErrorPage() OVERRIDE;
+  virtual void ReloadPage() OVERRIDE;
 
   void OnNetErrorInfo(int status);
   void OnSetAltErrorPageURL(const GURL& alternate_error_page_url);
 
   void OnAlternateErrorPageRetrieved(const blink::WebURLResponse& response,
                                      const std::string& data);
 
   scoped_ptr<content::ResourceFetcher> alt_error_page_fetcher_;
 
   NetErrorHelperCore core_;
 };
 
 #endif  // CHROME_RENDERER_NET_NET_ERROR_HELPER_H_