Update audio code to use size_t more correctly, talk/ portion.

talk/media/base/fakemediaengine.h

Index: talk/media/base/fakemediaengine.h
diff --git a/talk/media/base/fakemediaengine.h b/talk/media/base/fakemediaengine.h
index 15fcb202f1c667573beef7136f2bf92e6d50df8d..184541bbc08dfac1d84e08dd048b50f644baf626 100644
--- a/talk/media/base/fakemediaengine.h
+++ b/talk/media/base/fakemediaengine.h
@@ -438,7 +438,7 @@ class FakeVoiceMediaChannel : public RtpHelper<VoiceMediaChannel> {
                 int bits_per_sample,
                 int sample_rate,
                 int number_of_channels,
-                int number_of_frames) override {}
+                size_t number_of_frames) override {}
     void OnClose() override { renderer_ = NULL; }
     AudioRenderer* renderer() const { return renderer_; }