Add field trial for automic resize in MediaCodecVideoEncoder.

talk/app/webrtc/java/jni/androidmediaencoder_jni.cc

Index: talk/app/webrtc/java/jni/androidmediaencoder_jni.cc
diff --git a/talk/app/webrtc/java/jni/androidmediaencoder_jni.cc b/talk/app/webrtc/java/jni/androidmediaencoder_jni.cc
index 8c00bc3f51e5395fc1fdcfc1accd39d318ff9cce..5e83d2b8eff3e0ff3ffe7b21f08d3f8f7bc8a309 100644
--- a/talk/app/webrtc/java/jni/androidmediaencoder_jni.cc
+++ b/talk/app/webrtc/java/jni/androidmediaencoder_jni.cc
@@ -36,6 +36,7 @@
 #include "webrtc/modules/video_coding/codecs/interface/video_codec_interface.h"
 #include "webrtc/modules/video_coding/utility/include/quality_scaler.h"
 #include "webrtc/modules/video_coding/utility/include/vp8_header_parser.h"
+#include "webrtc/system_wrappers/interface/field_trial.h"
 #include "webrtc/system_wrappers/interface/logcat_trace_context.h"
 #include "third_party/libyuv/include/libyuv/convert.h"
 #include "third_party/libyuv/include/libyuv/convert_from.h"
@@ -296,7 +297,11 @@ int32_t MediaCodecVideoEncoder::InitEncode(
       codec_settings->codecType << " for " << codecType_;
 
   ALOGD("InitEncode request");
-  scale_ = false;
+
+  scale_ = webrtc::field_trial::FindFullName(
+      "WebRTC-MediaCodecVideoEncoder-AutomaticResize") == "Enabled";
+  ALOGD("Automatic resize: %s", scale_ ? "enabled" : "disabled");
+
   if (scale_ && codecType_ == kVideoCodecVP8) {
     quality_scaler_->Init(kMaxQP / kLowQpThresholdDenominator, true);
     quality_scaler_->SetMinResolution(kMinWidth, kMinHeight);