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

components/test/run_all_unittests.cc

Index: components/test/run_all_unittests.cc
diff --git a/components/test/run_all_unittests.cc b/components/test/run_all_unittests.cc
index 6476e591f7a93d539755a2d1bbc8770d2d1f2170..5cd4102f9f55014ecf5422a1ef4e9e39de409cb2 100644
--- a/components/test/run_all_unittests.cc
+++ b/components/test/run_all_unittests.cc
@@ -88,13 +88,13 @@ class ComponentsTestSuite : public base::TestSuite {
 class ComponentsUnitTestEventListener : public testing::EmptyTestEventListener {
  public:
   ComponentsUnitTestEventListener() {}
-  virtual ~ComponentsUnitTestEventListener() {}
+  ~ComponentsUnitTestEventListener() override {}
 
-  virtual void OnTestStart(const testing::TestInfo& test_info) override {
+  void OnTestStart(const testing::TestInfo& test_info) override {
     content_initializer_.reset(new content::TestContentClientInitializer());
   }
 
-  virtual void OnTestEnd(const testing::TestInfo& test_info) override {
+  void OnTestEnd(const testing::TestInfo& test_info) override {
     content_initializer_.reset();
   }