Remove the deprecated function ExtensionService::extensions().

chrome/browser/sync_file_system/drive_backend/sync_worker_unittest.cc

 // Copyright 2014 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/sync_file_system/drive_backend/sync_worker.h"
 
 #include "base/files/scoped_temp_dir.h"
 #include "base/run_loop.h"
 #include "base/strings/stringprintf.h"
 #include "base/thread_task_runner_handle.h"
@@ skipping 42 matching lines @@
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MockSyncTask);
 };
 
 class MockExtensionService : public TestExtensionService {
  public:
   MockExtensionService() {}
   ~MockExtensionService() override {}
 
-  const extensions::ExtensionSet* extensions() const override {
-    return &extensions_;
-  }
-
   void AddExtension(const extensions::Extension* extension) override {
     extensions_.Insert(make_scoped_refptr(extension));
   }
 
   const extensions::Extension* GetInstalledExtension(
       const std::string& extension_id) const override {
     return extensions_.GetByID(extension_id);
   }
 
   bool IsExtensionEnabled(const std::string& extension_id) const override {
@@ skipping 303 matching lines @@
       base::Bind(&SyncWorkerTest::CheckServiceState,
                  AsWeakPtr(),
                  SYNC_STATUS_OK,
                  REMOTE_SERVICE_OK));
 
   base::RunLoop().RunUntilIdle();
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system