Add a keypress field to the audioproc debug proto.

Log the value in AudioProcessing, and unpack it to a new file in the
unpacking tool.

TESTED=
- The new tool can unpack old dumps.
- The old tool can unpack new dumps (without keypress.bool).
- Unpacking a new dump from voe_cmd_test produces a keypress.bool that
appears correct when examined.

R=aluebs@webrtc.org, bjornv@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/8509005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5535 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/audio_processing/audio_processing_impl.cc

@@ -365,6 +365,7 @@ int AudioProcessingImpl::ProcessStream(AudioFrame* frame) {
     msg->set_delay(stream_delay_ms_);
     msg->set_drift(echo_cancellation_->stream_drift_samples());
     msg->set_level(gain_control_->stream_analog_level());
+    msg->set_keypress(key_pressed_);
   }
 #endif