Standardize usage of virtual/override/final specifiers.

content/renderer/render_view_browsertest.cc

Index: content/renderer/render_view_browsertest.cc
diff --git a/content/renderer/render_view_browsertest.cc b/content/renderer/render_view_browsertest.cc
index 1a23f58cbc272ef3f1c24ba16f6fb6d43b5f0df0..484d5d6c7eda2927d3e3fc66682fd0a20a716191 100644
--- a/content/renderer/render_view_browsertest.cc
+++ b/content/renderer/render_view_browsertest.cc
@@ -141,9 +141,9 @@ class RenderViewImplTest : public RenderViewTest {
     mock_keyboard_.reset(new MockKeyboard());
   }
 
-  virtual ~RenderViewImplTest() {}
+  ~RenderViewImplTest() override {}
 
-  virtual void SetUp() override {
+  void SetUp() override {
     RenderViewTest::SetUp();
     // Enable Blink's experimental and test only features so that test code
     // does not have to bother enabling each feature.