Move one CircularBuffer to webrtc::test namespace.

webrtc/modules/audio_coding/test/utility.h

Index: webrtc/modules/audio_coding/test/utility.h
diff --git a/webrtc/modules/audio_coding/test/utility.h b/webrtc/modules/audio_coding/test/utility.h
index 1a3e06d6c9668619bf822149c8091e0f28d70931..8af36751673426403738323920519a93a4129cd4 100644
--- a/webrtc/modules/audio_coding/test/utility.h
+++ b/webrtc/modules/audio_coding/test/utility.h
@@ -83,6 +83,9 @@ class ACMTestTimer {
   unsigned long _hour;
 };
 
+// To avoid clashes with CircularBuffer in APM.
+namespace test {
+
 class CircularBuffer {
  public:
   CircularBuffer(uint32_t len);
@@ -109,6 +112,8 @@ class CircularBuffer {
   double _sumSqr;
 };
 
+}  // namespace test
+
 int16_t ChooseCodec(CodecInst& codecInst);
 
 void PrintCodecs();