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

components/error_page/renderer/net_error_helper_core.cc

Index: components/error_page/renderer/net_error_helper_core.cc
diff --git a/components/error_page/renderer/net_error_helper_core.cc b/components/error_page/renderer/net_error_helper_core.cc
index db3f4dcd7d2e194e251d8e271e2ed181a2f2c710..f3104c32c80d2dcef0efce75eb3f2e1c9a578ca0 100644
--- a/components/error_page/renderer/net_error_helper_core.cc
+++ b/components/error_page/renderer/net_error_helper_core.cc
@@ -380,7 +380,8 @@ struct NetErrorHelperCore::ErrorPageInfo {
         reload_button_in_page(false),
         show_saved_copy_button_in_page(false),
         show_cached_copy_button_in_page(false),
-        show_saved_pages_button_in_page(false),
+        show_offline_pages_button_in_page(false),
+        show_offline_copy_button_in_page(false),
         is_finished_loading(false),
         auto_reload_triggered(false) {}
 
@@ -415,7 +416,8 @@ struct NetErrorHelperCore::ErrorPageInfo {
   bool reload_button_in_page;
   bool show_saved_copy_button_in_page;
   bool show_cached_copy_button_in_page;
-  bool show_saved_pages_button_in_page;
+  bool show_offline_pages_button_in_page;
+  bool show_offline_copy_button_in_page;
 
   // True if a page has completed loading, at which point it can receive
   // updates.
@@ -471,7 +473,7 @@ NetErrorHelperCore::NetErrorHelperCore(Delegate* delegate,
       visible_(is_visible),
       auto_reload_count_(0),
       navigation_from_button_(NO_BUTTON),
-      has_offline_pages_(false) {
+      offline_page_status_(OfflinePageStatus::NONE) {
 }
 
 NetErrorHelperCore::~NetErrorHelperCore() {
@@ -596,8 +598,11 @@ void NetErrorHelperCore::OnFinishLoad(FrameType frame_type) {
   if (committed_error_page_info_->show_saved_copy_button_in_page) {
     RecordEvent(NETWORK_ERROR_PAGE_SHOW_SAVED_COPY_BUTTON_SHOWN);
   }
-  if (committed_error_page_info_->show_saved_pages_button_in_page) {
-    RecordEvent(NETWORK_ERROR_PAGE_SHOW_SAVED_PAGES_BUTTON_SHOWN);
+  if (committed_error_page_info_->show_offline_pages_button_in_page) {
+    RecordEvent(NETWORK_ERROR_PAGE_SHOW_OFFLINE_PAGES_BUTTON_SHOWN);
+  }
+  if (committed_error_page_info_->show_offline_copy_button_in_page) {
+    RecordEvent(NETWORK_ERROR_PAGE_SHOW_OFFLINE_COPY_BUTTON_SHOWN);
   }
   if (committed_error_page_info_->reload_button_in_page &&
       committed_error_page_info_->show_saved_copy_button_in_page) {
@@ -653,15 +658,17 @@ void NetErrorHelperCore::GetErrorHTML(FrameType frame_type,
     bool reload_button_in_page;
     bool show_saved_copy_button_in_page;
     bool show_cached_copy_button_in_page;
-    bool show_saved_pages_button_in_page;
+    bool show_offline_pages_button_in_page;
+    bool show_offline_copy_button_in_page;
 
     delegate_->GenerateLocalizedErrorPage(
         error, is_failed_post,
         false /* No diagnostics dialogs allowed for subframes. */,
-        false /* No "show saved pages" provided in subframes */,
+        OfflinePageStatus::NONE /* No offline button provided in subframes */,
         scoped_ptr<ErrorPageParams>(), &reload_button_in_page,
         &show_saved_copy_button_in_page, &show_cached_copy_button_in_page,
-        &show_saved_pages_button_in_page, error_html);
+        &show_offline_pages_button_in_page,
+        &show_offline_copy_button_in_page, error_html);
   }
 }
 
@@ -697,8 +704,9 @@ void NetErrorHelperCore::OnSetNavigationCorrectionInfo(
   navigation_correction_params_.search_url = search_url;
 }
 
-void NetErrorHelperCore::OnSetHasOfflinePages(bool has_offline_pages) {
-  has_offline_pages_ = has_offline_pages;
+void NetErrorHelperCore::OnSetOfflinePageInfo(
+    OfflinePageStatus offline_page_status) {

[mmenke, 2015/11/17 21:02:15]

This seems racy - we could get information for the wrong page.

Consider:

1) We start navigate to http://blah/has_offline_data.
2) Navigation makes it to the browser UI thread, browser sends value, this gets
called with HAS_PAGE_COPY.
3) Navigation commits.
4) We start navigating to http://blah/has_no_offline_data
5) Request data from the IO Thread, get an error (Maybe it's blocked by policy
or something - no trip to UI thread needed)
6) Error page commits, incorrectly showing button.
7) Navigation makes it to the browser UI thread, browser sends correct value.

So how do we get accurate information?  We could send a URL, and compare it. 
I'm not sure there's a simpler option, though I'd really like one.  We can't,
for instance, attach it to the navigation information, without touching with
content, which I don't think we want to do.  Open to other ideas.

[jianli, 2015/11/19 02:23:46]

Yes, this has problem, but with navigating backward and forward. I fixed it by
sending the list of offline page URLs. Other solution will be far more
complicated than this.

+  offline_page_status_ = offline_page_status;
 }
 
 void NetErrorHelperCore::GetErrorHtmlForMainFrame(
@@ -728,12 +736,13 @@ void NetErrorHelperCore::GetErrorHtmlForMainFrame(
   delegate_->GenerateLocalizedErrorPage(
       error, pending_error_page_info->was_failed_post,
       can_show_network_diagnostics_dialog_,
-      has_offline_pages_,
+      offline_page_status_,
       scoped_ptr<ErrorPageParams>(),
       &pending_error_page_info->reload_button_in_page,
       &pending_error_page_info->show_saved_copy_button_in_page,
       &pending_error_page_info->show_cached_copy_button_in_page,
-      &pending_error_page_info->show_saved_pages_button_in_page,
+      &pending_error_page_info->show_offline_pages_button_in_page,
+      &pending_error_page_info->show_offline_copy_button_in_page,
       error_html);
 }
 
@@ -758,7 +767,7 @@ void NetErrorHelperCore::UpdateErrorPage() {
       GetUpdatedError(committed_error_page_info_->error),
       committed_error_page_info_->was_failed_post,
       can_show_network_diagnostics_dialog_,
-      has_offline_pages_);
+      offline_page_status_);
 }
 
 void NetErrorHelperCore::OnNavigationCorrectionsFetched(
@@ -796,12 +805,13 @@ void NetErrorHelperCore::OnNavigationCorrectionsFetched(
         pending_error_page_info_->error,
         pending_error_page_info_->was_failed_post,
         can_show_network_diagnostics_dialog_,
-        has_offline_pages_,
+        offline_page_status_,
         params.Pass(),
         &pending_error_page_info_->reload_button_in_page,
         &pending_error_page_info_->show_saved_copy_button_in_page,
         &pending_error_page_info_->show_cached_copy_button_in_page,
-        &pending_error_page_info_->show_saved_pages_button_in_page,
+        &pending_error_page_info_->show_offline_pages_button_in_page,
+        &pending_error_page_info_->show_offline_copy_button_in_page,
         &error_html);
   } else {
     // Since |navigation_correction_params| in |pending_error_page_info_| is
@@ -966,10 +976,15 @@ void NetErrorHelperCore::ExecuteButtonPress(Button button) {
       delegate_->DiagnoseError(
           committed_error_page_info_->error.unreachableURL);
       return;
-    case SHOW_SAVED_PAGES_BUTTON:
-      RecordEvent(NETWORK_ERROR_PAGE_SHOW_SAVED_PAGES_BUTTON_CLICKED);
+    case SHOW_OFFLINE_PAGES_BUTTON:
+      RecordEvent(NETWORK_ERROR_PAGE_SHOW_OFFLINE_PAGES_BUTTON_CLICKED);
       delegate_->ShowOfflinePages();
       return;
+    case SHOW_OFFLINE_COPY_BUTTON:
+      RecordEvent(NETWORK_ERROR_PAGE_SHOW_OFFLINE_COPY_BUTTON_CLICKED);
+      delegate_->LoadOfflineCopy(
+          committed_error_page_info_->error.unreachableURL);
+      return;
     case NO_BUTTON:
       NOTREACHED();
       return;