Clean up AudioProcessing defaults and errors.

- Remove unneeded #defines and switch the remainder to consts.
- All AudioProcessing components are disabled by default, so remove
explicit disables.
- AudioProcessing uses a rational 16 kHz mono default, so no need to
explictly initialize.
- Add assert(false) to real-time errors which should not occur.

TESTED=trybots
R=bjornv@webrtc.org, xians@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/2253005

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4924 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/voice_engine/voice_engine_defines.h b/voice_engine/voice_engine_defines.h
index 42851d4..8e5b24f 100644
--- a/voice_engine/voice_engine_defines.h
+++ b/voice_engine/voice_engine_defines.h
@@ -71,6 +71,7 @@
 #else
   true;
 #endif
+const GainControl::Mode kDefaultRxAgcMode = GainControl::kAdaptiveDigital;
 
 // Codec
 // Min init target rate for iSAC-wb
@@ -122,20 +123,6 @@
 
 }  // namespace webrtc
 
-// TODO(ajm): we shouldn't be using the precompiler for this.
-// Use enums or bools as appropriate.
-#define WEBRTC_VOICE_ENGINE_RX_AGC_DEFAULT_STATE false
-    // AudioProcessing RX AGC off
-#define WEBRTC_VOICE_ENGINE_RX_NS_DEFAULT_STATE false
-    // AudioProcessing RX NS off
-#define WEBRTC_VOICE_ENGINE_RX_HP_DEFAULT_STATE false
-    // AudioProcessing RX High Pass Filter off
-
-#define WEBRTC_VOICE_ENGINE_RX_AGC_DEFAULT_MODE GainControl::kAdaptiveDigital
-    // AudioProcessing AGC mode
-#define WEBRTC_VOICE_ENGINE_RX_NS_DEFAULT_MODE NoiseSuppression::kModerate
-    // AudioProcessing RX NS mode
-
 // ----------------------------------------------------------------------------
 //  Build information macros
 // ----------------------------------------------------------------------------