Enable new getUserMedia audio constraints algorithm behind a flag.

content/renderer/media/rtc_peer_connection_handler_unittest.cc

Index: content/renderer/media/rtc_peer_connection_handler_unittest.cc
diff --git a/content/renderer/media/rtc_peer_connection_handler_unittest.cc b/content/renderer/media/rtc_peer_connection_handler_unittest.cc
index ecc194664cbb08f4177b372fcbcf6be8c2e7f6c2..66d6be9f9b70739a3a690e57215acab1cfa33046 100644
--- a/content/renderer/media/rtc_peer_connection_handler_unittest.cc
+++ b/content/renderer/media/rtc_peer_connection_handler_unittest.cc
@@ -301,7 +301,7 @@ class RTCPeerConnectionHandlerTest : public ::testing::Test {
                              media::AudioParameters::kAudioCDSampleRate,
                              media::CHANNEL_LAYOUT_STEREO,
                              media::AudioParameters::kAudioCDSampleRate / 100),
-            MockConstraintFactory().CreateWebMediaConstraints(),
+            AudioProcessingProperties(),
             base::Bind(&RTCPeerConnectionHandlerTest::OnAudioSourceStarted),
             mock_dependency_factory_.get());
     audio_source->SetAllowInvalidRenderFrameIdForTesting(true);