Support auto-reload on errors.

chrome/renderer/net/net_error_helper_core.h

 // Copyright 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_CORE_H_
 #define CHROME_RENDERER_NET_NET_ERROR_HELPER_CORE_H_
 
 #include <string>
 
+#include "base/callback.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/common/net/net_error_info.h"
+#include "chrome/renderer/net/mockable_one_shot_timer.h"
 #include "url/gurl.h"
 
 namespace blink {
 struct WebURLError;
 }
 
 // Class that contains the logic for how the NetErrorHelper.  This allows for
 // testing the logic without a RenderView or WebFrame, which are difficult to
 // mock, and for testing races which are impossible to reliably reproduce
 // with real RenderViews or WebFrames.
@@ skipping 29 matching lines @@
                                  bool is_failed_post) = 0;
 
     // Fetches an error page and calls into OnErrorPageFetched when done.  Any
     // previous fetch must either be canceled or finished before calling.  Can't
     // be called synchronously after a previous fetch completes.
     virtual void FetchErrorPage(const GURL& url) = 0;
 
     // Cancels an error page fetch.  Does nothing if no fetch is ongoing.
     virtual void CancelFetchErrorPage() = 0;
 
+    // Starts a reload of the page in the observed frame.
+    virtual void ReloadPage() = 0;
+
    protected:
     virtual ~Delegate() {}
   };
 
-  explicit NetErrorHelperCore(Delegate* delegate);
+  NetErrorHelperCore(Delegate* delegate);
   ~NetErrorHelperCore();
 
   // 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(FrameType frame_type,
                     const blink::WebURLError& error,
                     bool is_failed_post,
                     std::string* error_html);
 
   // These methods handle tracking the actual state of the page.
   void OnStartLoad(FrameType frame_type, PageType page_type);
   void OnCommitLoad(FrameType frame_type);
   void OnFinishLoad(FrameType frame_type);
   void OnStop();
 
+  void CancelPendingFetches();
+
   // Called when an error page have has been retrieved over the network.  |html|
   // must be an empty string on error.
   void OnAlternateErrorPageFetched(const std::string& html);
 
   // Notifies |this| that network error information from the browser process
   // has been received.
   void OnNetErrorInfo(chrome_common_net::DnsProbeStatus status);
 
+  // Notifies |this| that the network's online status changed.
+  // Handler for NetworkStateChanged notification from the browser process. If
+  // the network state changes to online, this method is responsible for
+  // starting the auto-reload process.
+  //
+  // Warning: if there are many tabs sitting at an error page, this handler will
+  // be run at the same time for each of their top-level renderframes, which can
+  // cause many requests to be started at the same time. There's no current
+  // protection against this kind of "reload storm".
+  //
+  // TODO(rdsmith): prevent the reload storm.
+  void NetworkStateChanged(bool online);
+
   void set_alt_error_page_url(const GURL& alt_error_page_url) {
     alt_error_page_url_ = alt_error_page_url;
   }
 
+  void set_auto_reload_enabled(bool auto_reload_enabled) {
+    auto_reload_enabled_ = auto_reload_enabled;
+  }
+
+  int auto_reload_count() const { return auto_reload_count_; }
+
+  bool ShouldSuppressErrorPage(FrameType frame_type, const GURL& url);
+
+  void set_timer_for_testing(scoped_ptr<MockableOneShotTimer> timer) {
+    auto_reload_timer_.reset(timer.release());
+  }
+
  private:
   struct ErrorPageInfo;
 
   // Updates the currently displayed error page with a new error based on the
   // most recently received DNS probe result.  The page must have finished
   // loading before this is called.
   void UpdateErrorPage();
 
   void GenerateLocalErrorPage(
       FrameType frame_type,
       const blink::WebURLError& error,
       bool is_failed_post,
       std::string* error_html);
 
   blink::WebURLError GetUpdatedError(const blink::WebURLError& error) const;
 
+  void Reload();
+  bool MaybeStartAutoReloadTimer();
+  void StartAutoReloadTimer();
+
+  static bool IsReloadableError(const ErrorPageInfo& info);
+
   Delegate* delegate_;
 
   // The last DnsProbeStatus received from the browser.
   chrome_common_net::DnsProbeStatus last_probe_status_;
 
   // Information for the provisional / "pre-provisional" error page.  NULL when
   // there's no page pending, or the pending page is not an error page.
   scoped_ptr<ErrorPageInfo> pending_error_page_info_;
 
   // Information for the committed error page.  NULL when the committed page is
   // not an error page.
   scoped_ptr<ErrorPageInfo> committed_error_page_info_;
 
   GURL alt_error_page_url_;
+
+  bool auto_reload_enabled_;
+  scoped_ptr<MockableOneShotTimer> auto_reload_timer_;
+
+  // Is the browser online?
+  bool online_;
+
+  int auto_reload_count_;
+  bool can_auto_reload_page_;
 };
 
 #endif  // CHROME_RENDERER_NET_NET_ERROR_HELPER_CORE_H_