Update {virtual,override} to follow C++11 style in chrome.

chrome/browser/predictors/resource_prefetcher_unittest.cc

Index: chrome/browser/predictors/resource_prefetcher_unittest.cc
diff --git a/chrome/browser/predictors/resource_prefetcher_unittest.cc b/chrome/browser/predictors/resource_prefetcher_unittest.cc
index 4e68bdcda303adbea5d6b57a7bfd81fe3d8b3bad..efcd18d8adda8960eb7c27cc5cefa144b31a6894 100644
--- a/chrome/browser/predictors/resource_prefetcher_unittest.cc
+++ b/chrome/browser/predictors/resource_prefetcher_unittest.cc
@@ -33,7 +33,7 @@ class TestResourcePrefetcher : public ResourcePrefetcher {
       : ResourcePrefetcher(delegate, config, navigation_id,
                            key_type, requests.Pass()) { }
 
-  virtual ~TestResourcePrefetcher() { }
+  ~TestResourcePrefetcher() override {}
 
   MOCK_METHOD1(StartURLRequest, void(net::URLRequest* request));
 
@@ -55,7 +55,7 @@ class TestResourcePrefetcherDelegate : public ResourcePrefetcher::Delegate {
           loop->message_loop_proxy())) { }
   ~TestResourcePrefetcherDelegate() { }
 
-  virtual net::URLRequestContext* GetURLRequestContext() override {
+  net::URLRequestContext* GetURLRequestContext() override {
     return request_context_getter_->GetURLRequestContext();
   }