[Offline pages] Filter out pages cached by different tabs on tab helper

chrome/browser/android/offline_pages/recent_tab_helper.cc

 // Copyright (c) 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/recent_tab_helper.h"
 
 #include <queue>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "chrome/browser/android/offline_pages/offline_page_mhtml_archiver.h"
 #include "chrome/browser/android/offline_pages/offline_page_model_factory.h"
-#include "chrome/browser/android/tab_android.h"
+#include "chrome/browser/android/offline_pages/offline_page_utils.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 "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/navigation_handle.h"
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(offline_pages::RecentTabHelper);
 
 namespace {
 class DefaultDelegate: public offline_pages::RecentTabHelper::Delegate {
  public:
   DefaultDelegate() {}
 
   // offline_pages::RecentTabHelper::Delegate
   std::unique_ptr<offline_pages::OfflinePageArchiver> CreatePageArchiver(
       content::WebContents* web_contents) override {
     return base::MakeUnique<offline_pages::OfflinePageMHTMLArchiver>(
         web_contents);
   }
   scoped_refptr<base::SingleThreadTaskRunner> GetTaskRunner() override {
     return base::ThreadTaskRunnerHandle::Get();
   }
   bool GetTabId(content::WebContents* web_contents, int* tab_id) override {
-    TabAndroid* tab_android = TabAndroid::FromWebContents(web_contents);
-    if (!tab_android)
-      return false;
-    *tab_id = tab_android->GetAndroidId();
-    return true;
+    return offline_pages::OfflinePageUtils::GetTabId(web_contents, tab_id);
   }
 };
 }  // namespace
 
 namespace offline_pages {
 
 RecentTabHelper::RecentTabHelper(content::WebContents* web_contents)
     : content::WebContentsObserver(web_contents),
       page_model_(nullptr),
       delegate_(new DefaultDelegate()),
@@ skipping 124 matching lines @@
 bool RecentTabHelper::IsSamePage() const {
   return web_contents() &&
          (web_contents()->GetLastCommittedURL() == snapshot_url_);
 }
 
 ClientId RecentTabHelper::client_id() const {
   return ClientId(kLastNNamespace, tab_id_);
 }
 
 }  // namespace offline_pages