RtcVideoEncoder: determine video codec profile at InitEncode time.

content/renderer/media/rtc_video_encoder.h

Index: content/renderer/media/rtc_video_encoder.h
diff --git a/content/renderer/media/rtc_video_encoder.h b/content/renderer/media/rtc_video_encoder.h
index 43852ef66a3bbf7dfe5b8acf8ddb18d311976095..c32e42d5953f053294b7198011d70c93e2412717 100644
--- a/content/renderer/media/rtc_video_encoder.h
+++ b/content/renderer/media/rtc_video_encoder.h
@@ -47,7 +47,6 @@ class CONTENT_EXPORT RTCVideoEncoder
  public:
   RTCVideoEncoder(
       webrtc::VideoCodecType type,
-      media::VideoCodecProfile profile,
       const scoped_refptr<media::GpuVideoAcceleratorFactories>& gpu_factories);
   virtual ~RTCVideoEncoder();
 
@@ -85,7 +84,7 @@ class CONTENT_EXPORT RTCVideoEncoder
   const webrtc::VideoCodecType video_codec_type_;
 
   // The video codec profile, to configure the encoder to encode to.
-  const media::VideoCodecProfile video_codec_profile_;
+  media::VideoCodecProfile video_codec_profile_;
 
   // Factory for creating VEAs, shared memory buffers, etc.
   scoped_refptr<media::GpuVideoAcceleratorFactories> gpu_factories_;