Enable download page action for error page

chrome/browser/net/net_error_tab_helper.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 CHROME_BROWSER_NET_NET_ERROR_TAB_HELPER_H_
 #define CHROME_BROWSER_NET_NET_ERROR_TAB_HELPER_H_
 
 #include <string>
 
 #include "base/bind.h"
@@ skipping 33 matching lines @@
   static void set_state_for_testing(TestingState testing_state);
 
   // Sets a callback that will be called immediately after the helper sends
   // a NetErrorHelper IPC.  (Used by the DNS probe browser test to know when to
   // check the error page for updates, instead of polling.)
   void set_dns_probe_status_snoop_callback_for_testing(
       const DnsProbeStatusSnoopCallback& dns_probe_status_snoop_callback) {
     dns_probe_status_snoop_callback_ = dns_probe_status_snoop_callback;
   }
 
+#if defined(OS_ANDROID)
+  bool is_showing_download_button_in_error_page() const {
+    return is_showing_download_button_in_error_page_;
+  }
+#endif  // defined(OS_ANDROID)
+
   // content::WebContentsObserver implementation.
   void RenderFrameCreated(content::RenderFrameHost* render_frame_host) override;
   void DidStartNavigation(
       content::NavigationHandle* navigation_handle) override;
   void DidFinishNavigation(
       content::NavigationHandle* navigation_handle) override;
   bool OnMessageReceived(const IPC::Message& message,
                          content::RenderFrameHost* render_frame_host) override;
 
  protected:
   // |contents| is the WebContents of the tab this NetErrorTabHelper is
   // attached to.
   explicit NetErrorTabHelper(content::WebContents* contents);
   virtual void StartDnsProbe();
   virtual void SendInfo();
   void OnDnsProbeFinished(error_page::DnsProbeStatus result);
 
   error_page::DnsProbeStatus dns_probe_status() const {
     return dns_probe_status_;
   }
 
   content::WebContentsFrameBindingSet<chrome::mojom::NetworkDiagnostics>&
   network_diagnostics_bindings_for_testing() {
     return network_diagnostics_bindings_;
   }
 
 #if defined(OS_ANDROID)
-  void DownloadPageLater();
+  void OnDownloadPageLater();
+  void OnSetIsShowingDownloadButtonInErrorPage(bool is_showing_download_button);
 #endif  // defined(OS_ANDROID)
 
  private:
   friend class content::WebContentsUserData<NetErrorTabHelper>;
 
   void OnMainFrameDnsError();
 
   void InitializePref(content::WebContents* contents);
   bool ProbesAllowed() const;
 
@@ skipping 16 matching lines @@
   bool is_error_page_;
 
   // True if the helper has seen a main frame page load fail with a DNS error,
   // but has not yet seen a new page commit successfully afterwards.
   bool dns_error_active_;
 
   // True if the helper has seen an error page commit while |dns_error_active_|
   // is true.  (This should never be true if |dns_error_active_| is false.)
   bool dns_error_page_committed_;
 
+#if defined(OS_ANDROID)
+  // True if download button is being shown when the error page commits.
+  bool is_showing_download_button_in_error_page_;
+#endif  // defined(OS_ANDROID)
+
   // The status of a DNS probe that may or may not have started or finished.
   // Since the renderer can change out from under the helper (in cross-process
   // navigations), it re-sends the status whenever an error page commits.
   error_page::DnsProbeStatus dns_probe_status_;
 
   // Optional callback for browser test to snoop on outgoing NetErrorInfo IPCs.
   DnsProbeStatusSnoopCallback dns_probe_status_snoop_callback_;
 
   // "Use a web service to resolve navigation errors" preference is required
   // to allow probes.
   BooleanPrefMember resolve_errors_with_web_service_;
 
   base::WeakPtrFactory<NetErrorTabHelper> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NetErrorTabHelper);
 };
 
 }  // namespace chrome_browser_net
 
 #endif  // CHROME_BROWSER_NET_NET_ERROR_TAB_HELPER_H_