Add layout tests for the audio component of MediaStream Recording.

components/test_runner/web_test_delegate.h

Index: components/test_runner/web_test_delegate.h
diff --git a/components/test_runner/web_test_delegate.h b/components/test_runner/web_test_delegate.h
index 893cbae478c107bac90ec8e3a32205e497df5e2c..753831db711f65fdb65e6150467cf11480ba8787 100644
--- a/components/test_runner/web_test_delegate.h
+++ b/components/test_runner/web_test_delegate.h
@@ -250,7 +250,10 @@ class WebTestDelegate {
   virtual void ResetPermissions() = 0;
 
   // Add content MediaStream classes to the Blink MediaStream ones.
-  virtual bool AddMediaStreamSourceAndTrack(blink::WebMediaStream* stream) = 0;
+  virtual bool AddMediaStreamVideoSourceAndTrack(
+      blink::WebMediaStream* stream) = 0;
+  virtual bool AddMediaStreamAudioSourceAndTrack(
+      blink::WebMediaStream* stream) = 0;
 
   virtual cc::SharedBitmapManager* GetSharedBitmapManager() = 0;