Collapse AudioRendererMixer and OnMoreDataResampler into AudioTransform.

media/base/fake_audio_render_callback.cc

Index: media/base/fake_audio_render_callback.cc
diff --git a/media/base/fake_audio_render_callback.cc b/media/base/fake_audio_render_callback.cc
index 65b6ac95f7efd830f284799a4c6e7ccddc166506..dd9b0730230920dbab466aaf9806e7275e95e7dc 100644
--- a/media/base/fake_audio_render_callback.cc
+++ b/media/base/fake_audio_render_callback.cc
@@ -5,16 +5,17 @@
 // MSVC++ requires this to be set before any other includes to get M_PI.
 #define _USE_MATH_DEFINES
 
-#include "media/base/fake_audio_render_callback.h"
-
 #include <cmath>
 
+#include "media/base/fake_audio_render_callback.h"
+
 namespace media {
 
 FakeAudioRenderCallback::FakeAudioRenderCallback(double step)
     : half_fill_(false),
       step_(step),
-      last_audio_delay_milliseconds_(-1) {
+      last_audio_delay_milliseconds_(-1),
+      volume_(1) {
   reset();
 }
 
@@ -40,4 +41,10 @@ int FakeAudioRenderCallback::Render(AudioBus* audio_bus,
   return number_of_frames;
 }
 
+float FakeAudioRenderCallback::ProvideAudioTransformInput(
+    AudioBus* audio_bus, base::TimeDelta buffer_delay) {
+  Render(audio_bus, buffer_delay.InMilliseconds());
+  return volume_;
+}
+
 }  // namespace media