Enforce marking "override" for functions overriding Blink.

content/child/service_worker/service_worker_dispatcher_unittest.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 "content/child/service_worker/service_worker_dispatcher.h"
 #include "content/child/service_worker/service_worker_handle_reference.h"
 #include "content/child/service_worker/service_worker_provider_context.h"
 #include "content/child/service_worker/web_service_worker_impl.h"
 #include "content/child/service_worker/web_service_worker_registration_impl.h"
 #include "content/child/thread_safe_sender.h"
@@ skipping 98 matching lines @@
 
 class MockWebServiceWorkerProviderClientImpl
     : public blink::WebServiceWorkerProviderClient {
  public:
   MockWebServiceWorkerProviderClientImpl(int provider_id,
                                          ServiceWorkerDispatcher* dispatcher)
       : provider_id_(provider_id), dispatcher_(dispatcher) {
     dispatcher_->AddProviderClient(provider_id, this);
   }
 
-  ~MockWebServiceWorkerProviderClientImpl() {
+  ~MockWebServiceWorkerProviderClientImpl() override {
     dispatcher_->RemoveProviderClient(provider_id_);
   }
 
   void setController(
       blink::WebPassOwnPtr<blink::WebServiceWorker::Handle> handle,
-      bool shouldNotifyControllerChange) {
+      bool shouldNotifyControllerChange) override {
     // WebPassOwnPtr cannot be owned in Chromium, so drop the handle here.
     // The destruction releases ServiceWorkerHandleReference.
     is_set_controlled_called_ = true;
   }
 
   void dispatchMessageEvent(
       blink::WebPassOwnPtr<blink::WebServiceWorker::Handle> handle,
       const blink::WebString& message,
       const blink::WebMessagePortChannelArray& channels) override {
     // WebPassOwnPtr cannot be owned in Chromium, so drop the handle here.
@@ skipping 377 matching lines @@
             ipc_sink()->GetMessageAt(0)->type());
   EXPECT_EQ(ServiceWorkerHostMsg_DecrementServiceWorkerRefCount::ID,
             ipc_sink()->GetMessageAt(1)->type());
   EXPECT_EQ(ServiceWorkerHostMsg_DecrementServiceWorkerRefCount::ID,
             ipc_sink()->GetMessageAt(2)->type());
   EXPECT_EQ(ServiceWorkerHostMsg_DecrementRegistrationRefCount::ID,
             ipc_sink()->GetMessageAt(3)->type());
 }
 
 }  // namespace content