Replace AudioFrame's operator= with CopyFrom().

Enforce DISALLOW_COPY_AND_ASSIGN to catch offenders.

Review URL: https://webrtc-codereview.appspot.com/1031007

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3395 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/utility/source/coder.cc

@@ -92,7 +92,8 @@ WebRtc_Word32 AudioCoder::Encode(const AudioFrame& audio,
 {
     // Fake a timestamp in case audio doesn't contain a correct timestamp.
     // Make a local copy of the audio frame since audio is const
-    AudioFrame audioFrame = audio;
+    AudioFrame audioFrame;
+    audioFrame.CopyFrom(audio);
     audioFrame.timestamp_ = _encodeTimestamp;
     _encodeTimestamp += audioFrame.samples_per_channel_;