Added A/V sync tests with drifting clocks.

webrtc/test/call_test.h

Index: webrtc/test/call_test.h
diff --git a/webrtc/test/call_test.h b/webrtc/test/call_test.h
index 251d7f6044df6c93552c84447880a268bc8baae5..b1ca2e5e727d642cf76e086f264ecead601fbcae 100644
--- a/webrtc/test/call_test.h
+++ b/webrtc/test/call_test.h
@@ -71,6 +71,8 @@ class CallTest : public ::testing::Test {
                         Transport* send_transport);
   void CreateMatchingReceiveConfigs(Transport* rtcp_send_transport);
 
+  void CreateFrameGeneratorCapturerWithDrift(Clock* drift_clock, float drift);
+  void CreateFakeAudioDevicesWithDrift(float drift);
   void CreateFrameGeneratorCapturer();
   void CreateFakeAudioDevices();