Fix IsPrecachingAllowed() to check Sync instead of Data Saver.

components/precache/content/precache_manager.h

 // Copyright 2013 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.
 
 #ifndef COMPONENTS_PRECACHE_CONTENT_PRECACHE_MANAGER_H_
 #define COMPONENTS_PRECACHE_CONTENT_PRECACHE_MANAGER_H_
 
 #include <list>
 #include <string>
 #include <utility>
@@ skipping 14 matching lines @@
 }
 
 namespace content {
 class BrowserContext;
 }
 
 namespace history {
 class HistoryService;
 }
 
+namespace sync_driver {
+class SyncService;
+}
+
 namespace precache {
 
 class PrecacheDatabase;
 
 // Visible for test.
 int NumTopHosts();
 
 // Class that manages all precaching-related activities. Owned by the
 // BrowserContext that it is constructed for. Use
 // PrecacheManagerFactory::GetForBrowserContext to get an instance of this
 // class. All methods must be called on the UI thread unless indicated
 // otherwise.
 // TODO(sclittle): Delete precache history when browsing history is deleted.
 // http://crbug.com/326549
 class PrecacheManager : public KeyedService,
                         public PrecacheFetcher::PrecacheDelegate,
                         public base::SupportsWeakPtr<PrecacheManager> {
  public:
   typedef base::Closure PrecacheCompletionCallback;
 
-  explicit PrecacheManager(content::BrowserContext* browser_context);
+  PrecacheManager(content::BrowserContext* browser_context,
+                  const sync_driver::SyncService* const sync_service);
   ~PrecacheManager() override;
 
   // Returns true if precaching is enabled as part of a field trial or by the
   // command line flag. This method can be called on any thread.
   static bool IsPrecachingEnabled();
 
   // Returns true if precaching is allowed for the browser context.
   bool IsPrecachingAllowed();
 
   // Starts precaching resources that the user is predicted to fetch in the
@@ skipping 20 matching lines @@
   // From KeyedService.
   void Shutdown() override;
 
   // From PrecacheFetcher::PrecacheDelegate.
   void OnDone() override;
 
   // From history::HistoryService::TopHosts.
   void OnHostsReceived(const history::TopHostsList& host_counts);
 
   // The browser context that owns this PrecacheManager.
-  content::BrowserContext* browser_context_;
+  content::BrowserContext* const browser_context_;
+
+  // The sync service corresponding to the browser context. Used to determine
+  // whether precache can run. May be null.
+  const sync_driver::SyncService* const sync_service_;
 
   // The PrecacheFetcher used to precache resources. Should only be used on the
   // UI thread.
   scoped_ptr<PrecacheFetcher> precache_fetcher_;
 
   // The callback that will be run if precaching finishes without being
   // canceled.
   PrecacheCompletionCallback precache_completion_callback_;
 
   // The PrecacheDatabase for tracking precache metrics. Should only be used on
   // the DB thread.
-  scoped_refptr<PrecacheDatabase> precache_database_;
+  const scoped_refptr<PrecacheDatabase> precache_database_;
 
   // Flag indicating whether or not precaching is currently in progress.
   bool is_precaching_;
 
   DISALLOW_COPY_AND_ASSIGN(PrecacheManager);
 };
 
 }  // namespace precache
 
 #endif  // COMPONENTS_PRECACHE_CONTENT_PRECACHE_MANAGER_H_