Refactors offline page tab helper to stash the offline page item on redirect.

chrome/browser/android/offline_pages/offline_page_utils.cc

 // Copyright 2015 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/android/offline_pages/offline_page_utils.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/string_util.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/android/offline_pages/offline_page_mhtml_archiver.h"
 #include "chrome/browser/android/offline_pages/offline_page_model_factory.h"
 #include "components/offline_pages/offline_page_feature.h"
 #include "components/offline_pages/offline_page_item.h"
 #include "components/offline_pages/offline_page_model.h"
 #include "content/public/browser/browser_context.h"
+#include "content/public/browser/web_contents.h"
 #include "url/gurl.h"
 
 namespace offline_pages {
 namespace {
 
+const char kWebContentsUserDataKey[] = "OfflinePageForTab";
+
 // Returns an offline page originated from the |online_url|.
 const OfflinePageItem* MaybeGetBestOfflinePageForOnlineURL(
     content::BrowserContext* browser_context,
     const GURL& online_url) {
   DCHECK(browser_context);
 
   if (!IsOfflinePagesEnabled())
     return nullptr;
 
   OfflinePageModel* offline_page_model =
@@ skipping 138 matching lines @@
       GetOfflinePageForOfflineURL(browser_context, offline_url);
   if (!offline_page)
     return;
 
   OfflinePageModel* offline_page_model =
       OfflinePageModelFactory::GetForBrowserContext(browser_context);
   DCHECK(offline_page_model);
   offline_page_model->MarkPageAccessed(offline_page->offline_id);
 }
 
+const OfflinePageItem* OfflinePageUtils::GetCurrentOfflinePage(
+    content::WebContents* web_contents) {
+  return static_cast<const OfflinePageItem*>(
+      web_contents->GetUserData(kWebContentsUserDataKey));
+}
+
+void OfflinePageUtils::SetCurrentOfflinePage(
+    content::WebContents* web_contents,
+    const OfflinePageItem* offline_page) {
+  if (!offline_page) {
+    web_contents->RemoveUserData(kWebContentsUserDataKey);
+    return;
+  }
+
+  // |SetUserData| takes ownership of the data object, so we need to make a copy
+  // here.
+  web_contents->SetUserData(kWebContentsUserDataKey,
+                            new OfflinePageItem(*offline_page));
+}
 }  // namespace offline_pages