Standardize usage of virtual/override/final specifiers.

content/browser/media/webrtc_getusermedia_browsertest.cc

Index: content/browser/media/webrtc_getusermedia_browsertest.cc
diff --git a/content/browser/media/webrtc_getusermedia_browsertest.cc b/content/browser/media/webrtc_getusermedia_browsertest.cc
index f0bc828f57b0027f3c854cdff7126fbdd138bd42..8c8bf2dba098d3f80ae4637f5eac4ca32f25aa25 100644
--- a/content/browser/media/webrtc_getusermedia_browsertest.cc
+++ b/content/browser/media/webrtc_getusermedia_browsertest.cc
@@ -78,7 +78,7 @@ namespace content {
 class WebRtcGetUserMediaBrowserTest: public WebRtcContentBrowserTest {
  public:
   WebRtcGetUserMediaBrowserTest() : trace_log_(NULL) {}
-  virtual ~WebRtcGetUserMediaBrowserTest() {}
+  ~WebRtcGetUserMediaBrowserTest() override {}
 
   void StartTracing() {
     CHECK(trace_log_ == NULL) << "Can only can start tracing once";