Add support for midstream audio configuration changes.

media/filters/pipeline_integration_test_base.h

Index: media/filters/pipeline_integration_test_base.h
diff --git a/media/filters/pipeline_integration_test_base.h b/media/filters/pipeline_integration_test_base.h
index 39d2e2cb72cd9722b5d65bcb7776768af23c36ec..25a5924cc87fa370b83f60b0d7846185f160c9e5 100644
--- a/media/filters/pipeline_integration_test_base.h
+++ b/media/filters/pipeline_integration_test_base.h
@@ -9,6 +9,7 @@
 #include "base/message_loop/message_loop.h"
 #include "media/audio/clockless_audio_sink.h"
 #include "media/audio/null_audio_sink.h"
+#include "media/base/audio_hardware_config.h"
 #include "media/base/demuxer.h"
 #include "media/base/filter_collection.h"
 #include "media/base/media_keys.h"
@@ -109,6 +110,7 @@ class PipelineIntegrationTestBase {
   Demuxer::NeedKeyCB need_key_cb_;
   VideoFrame::Format last_video_frame_format_;
   DummyTickClock dummy_clock_;
+  AudioHardwareConfig hardware_config_;
 
   void OnStatusCallbackChecked(PipelineStatus expected_status,
                                PipelineStatus status);