Enable -Winconsistent-missing-override flag.

webrtc/api/test/fakeaudiocapturemodule.h

Index: webrtc/api/test/fakeaudiocapturemodule.h
diff --git a/webrtc/api/test/fakeaudiocapturemodule.h b/webrtc/api/test/fakeaudiocapturemodule.h
index 30ad3f8b71feaca1b42234b11bcdc3bd4c989984..098243f1c65caadbeecacfa98dbf2c6856b99987 100644
--- a/webrtc/api/test/fakeaudiocapturemodule.h
+++ b/webrtc/api/test/fakeaudiocapturemodule.h
@@ -174,12 +174,12 @@ class FakeAudioCaptureModule
   int32_t ResetAudioDevice() override;
   int32_t SetLoudspeakerStatus(bool enable) override;
   int32_t GetLoudspeakerStatus(bool* enabled) const override;
-  virtual bool BuiltInAECIsAvailable() const { return false; }
-  virtual int32_t EnableBuiltInAEC(bool enable) { return -1; }
-  virtual bool BuiltInAGCIsAvailable() const { return false; }
-  virtual int32_t EnableBuiltInAGC(bool enable) { return -1; }
-  virtual bool BuiltInNSIsAvailable() const { return false; }
-  virtual int32_t EnableBuiltInNS(bool enable) { return -1; }
+  bool BuiltInAECIsAvailable() const override { return false; }
+  int32_t EnableBuiltInAEC(bool enable) override { return -1; }
+  bool BuiltInAGCIsAvailable() const override { return false; }
+  int32_t EnableBuiltInAGC(bool enable) override { return -1; }
+  bool BuiltInNSIsAvailable() const override { return false; }
+  int32_t EnableBuiltInNS(bool enable) override { return -1; }
   // End of functions inherited from webrtc::AudioDeviceModule.
 
   // The following function is inherited from rtc::MessageHandler.