Add "Show saved copy" button in dino page when there's offline copy

chrome/browser/net/net_error_tab_helper.cc

 // 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.
 
 #include "chrome/browser/net/net_error_tab_helper.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/io_thread.h"
 #include "chrome/browser/net/dns_probe_service.h"
 #include "chrome/browser/net/net_error_diagnostics_dialog.h"
 #include "chrome/browser/platform_util.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/common/localized_error.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/render_messages.h"
 #include "components/error_page/common/net_error_info.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/navigation_entry.h"
+#include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/render_frame_host.h"
 #include "ipc/ipc_message_macros.h"
 #include "net/base/net_errors.h"
 #include "url/gurl.h"
 
 #if defined(OS_ANDROID)
+#include "chrome/browser/android/offline_pages/offline_page_model_factory.h"
 #include "chrome/browser/android/tab_android.h"
-#endif
+#include "components/offline_pages/offline_page_feature.h"
+#include "components/offline_pages/offline_page_item.h"
+#include "components/offline_pages/offline_page_model.h"
+#endif  // defined(OS_ANDROID)
 
 using content::BrowserContext;
 using content::BrowserThread;
 using content::WebContents;
 using content::WebContentsObserver;
 using error_page::DnsProbeStatus;
 using error_page::DnsProbeStatusToString;
+using error_page::OfflinePageStatus;
 using ui::PageTransition;
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(chrome_browser_net::NetErrorTabHelper);
 
 namespace chrome_browser_net {
 
 namespace {
 
 static NetErrorTabHelper::TestingState testing_state_ =
     NetErrorTabHelper::TESTING_DEFAULT;
@@ skipping 72 matching lines @@
     bool is_error_page,
     bool is_iframe_srcdoc) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   if (render_frame_host->GetParent())
     return;
 
   is_error_page_ = is_error_page;
 
 #if defined(OS_ANDROID)
-  SetHasOfflinePages(render_frame_host);
-#endif
+  SetOfflinePageInfo(render_frame_host, validated_url);
+#endif  // defined(OS_ANDROID)
 }
 
 void NetErrorTabHelper::DidCommitProvisionalLoadForFrame(
     content::RenderFrameHost* render_frame_host,
     const GURL& url,
     PageTransition transition_type) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   if (render_frame_host->GetParent())
     return;
@@ skipping 31 matching lines @@
 
 bool NetErrorTabHelper::OnMessageReceived(
     const IPC::Message& message,
     content::RenderFrameHost* render_frame_host) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(NetErrorTabHelper, message)
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_RunNetworkDiagnostics,
                         RunNetworkDiagnostics)
 #if defined(OS_ANDROID)
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_ShowOfflinePages, ShowOfflinePages)
-#endif
+    IPC_MESSAGE_HANDLER(ChromeViewHostMsg_LoadOfflineCopy, LoadOfflineCopy)
+#endif  // defined(OS_ANDROID)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
   return handled;
 }
 
 NetErrorTabHelper::NetErrorTabHelper(WebContents* contents)
     : WebContentsObserver(contents),
       is_error_page_(false),
       dns_error_active_(false),
@@ skipping 88 matching lines @@
   // Sanitize URL prior to running diagnostics on it.
   RunNetworkDiagnosticsHelper(url.GetOrigin().spec());
 }
 
 void NetErrorTabHelper::RunNetworkDiagnosticsHelper(
     const std::string& sanitized_url) {
   ShowNetworkDiagnosticsDialog(web_contents(), sanitized_url);
 }
 
 #if defined(OS_ANDROID)
-void NetErrorTabHelper::SetHasOfflinePages(
-  content::RenderFrameHost* render_frame_host) {
-  DCHECK(web_contents());
-  TabAndroid* tab = TabAndroid::FromWebContents(web_contents());
-  bool has_offline_pages = tab && tab->HasOfflinePages();
+void NetErrorTabHelper::SetOfflinePageInfo(
+    content::RenderFrameHost* render_frame_host, const GURL& url) {
+  // Bails out if offline pages not supported.
+  if (!offline_pages::IsOfflinePagesEnabled())
+    return;

[mmenke, 2015/11/23 19:55:22]

nit:  Suggest blank lines after this return and the next, to make the code
easier to read.

[jianli, 2015/11/23 22:08:34]

Done.

+  offline_pages::OfflinePageModel* offline_page_model =
+      offline_pages::OfflinePageModelFactory::GetForBrowserContext(
+          Profile::FromBrowserContext(web_contents()->GetBrowserContext()));
+  if (!offline_page_model)
+    return;
+  OfflinePageStatus status = OfflinePageStatus::NONE;
+  if (offline_page_model->HasOfflinePages())

[mmenke, 2015/11/23 19:54:26]

nit:  Use braces.

[jianli, 2015/11/23 22:08:34]

Done.

+    status = offline_page_model->GetPageByOnlineURL(url) ?
+        OfflinePageStatus::HAS_OFFLINE_PAGE :
+        OfflinePageStatus::HAS_OTHER_OFFLINE_PAGES;
   render_frame_host->Send(
-      new ChromeViewMsg_SetHasOfflinePages(
-          render_frame_host->GetRoutingID(),
-          has_offline_pages));
+      new ChromeViewMsg_SetOfflinePageInfo(
+          render_frame_host->GetRoutingID(), status));
 }
 
 void NetErrorTabHelper::ShowOfflinePages() {
+  // Makes sure that this is coming from from an error page.
+  if (!IsFromErrorPage())
+    return;
+
   DCHECK(web_contents());
   TabAndroid* tab = TabAndroid::FromWebContents(web_contents());
   if (tab)
     tab->ShowOfflinePages();
 }
-#endif
+
+void NetErrorTabHelper::LoadOfflineCopy(const GURL& url) {
+  // Makes sure that this is coming from from an error page.
+  if (!IsFromErrorPage())
+    return;
+
+  GURL validated_url(url);

[mmenke, 2015/11/23 19:54:26]

I don't think you need to make a copy here?  can just use url everywhere.

[jianli, 2015/11/23 22:08:34]

This is introduced based on nasko's comment:
Since this URL comes from the renderer, it cannot be directly trusted.
It needs to be validated first. The pattern used is:

GURL validated_url(url);
if (validated_url.is_valid())
  // do whatever is correct for invalid URLs, here probably just return

[mmenke, 2015/11/23 22:15:14]

Sorry, I missed Nasko's comment.  I completely to defer to Nasko on that.

+  if (!validated_url.is_valid())
+    return;
+
+  DCHECK(web_contents());
+  if (validated_url != web_contents()->GetURL())
+    return;
+
+  TabAndroid* tab = TabAndroid::FromWebContents(web_contents());
+  if (tab)
+    tab->LoadOfflineCopy(url);
+}
+
+bool NetErrorTabHelper::IsFromErrorPage() const {
+  content::NavigationEntry* entry =
+      web_contents()->GetController().GetLastCommittedEntry();
+  if (!entry)
+    return false;
+  return entry->GetPageType() == content::PAGE_TYPE_ERROR;
+}
+
+#endif  // defined(OS_ANDROID)
 
 }  // namespace chrome_browser_net