Allow opening an offline download file as offline page

chrome/browser/android/offline_pages/offline_page_tab_helper.cc

 // Copyright 2016 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_tab_helper.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "chrome/browser/android/offline_pages/offline_page_model_factory.h"
 #include "chrome/browser/android/offline_pages/offline_page_utils.h"
 #include "chrome/browser/net/nqe/ui_network_quality_estimator_service.h"
 #include "chrome/browser/net/nqe/ui_network_quality_estimator_service_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "components/offline_pages/client_namespace_constants.h"
+#include "components/offline_pages/offline_page_item.h"
 #include "components/offline_pages/offline_page_model.h"
 #include "components/previews/previews_experiments.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
 #include "net/base/net_errors.h"
 #include "net/base/network_change_notifier.h"
@@ skipping 66 matching lines @@
   // This is a new navigation so we can invalidate any previously scheduled
   // operations.
   weak_ptr_factory_.InvalidateWeakPtrs();
 
   // Since this is a new navigation, we will reset the cached offline page,
   // unless we are currently looking at an offline page.
   GURL navigated_url = navigation_handle->GetURL();
   if (offline_page_ && navigated_url != offline_page_->GetOfflineURL())
     offline_page_ = nullptr;
 
+  // If an offline download file is opened, don't do redirect per network
+  // conditions. Also store a cached copy here such that Tab knows that
+  // the offline page is opened.
+  if (OfflinePageUtils::MightBeOfflineURL(navigated_url)) {
+    OfflinePageModel* offline_page_model =
+        OfflinePageModelFactory::GetForBrowserContext(
+            web_contents()->GetBrowserContext());
+    if (offline_page_model) {
+      const OfflinePageItem* offline_page =
+          offline_page_model->MaybeGetPageByOfflineURL(navigated_url);
+      if (offline_page &&
+          offline_page->client_id.name_space == kDownloadNamespace) {
+        offline_page_ = base::MakeUnique<OfflinePageItem>(*offline_page);
+        return;
+      }
+    }
+  }
+
   // Ignore navigations that are forward or back transitions in the nav stack
   // which are not at the head of the stack.
   // TODO(dimich): Not sure this is needed. Clarify and remove. Bug 624216.
   const content::NavigationController& controller =
       web_contents()->GetController();
   if (controller.GetEntryCount() > 0 &&
       controller.GetCurrentEntryIndex() != -1 &&
       controller.GetCurrentEntryIndex() < controller.GetEntryCount() - 1) {
     return;
   }
@@ skipping 184 matching lines @@
          entry->GetRedirectChain().back() == to_url;
 }
 
 void OfflinePageTabHelper::ReportRedirectResultUMA(RedirectResult result) {
   UMA_HISTOGRAM_ENUMERATION("OfflinePages.RedirectResult",
       static_cast<int>(result),
       static_cast<int>(RedirectResult::REDIRECT_RESULT_MAX));
 }
 
 }  // namespace offline_pages