RtcVideo{Encoder,Decoder}{Factory,} minor cleanup: consts, range based loops, comments.

content/renderer/media/rtc_video_encoder_factory.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_MEDIA_RTC_VIDEO_ENCODER_FACTORY_H_
 #define CONTENT_RENDERER_MEDIA_RTC_VIDEO_ENCODER_FACTORY_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 #include "third_party/libjingle/source/talk/media/webrtc/webrtcvideoencoderfactory.h"
 
 namespace media {
-
 class GpuVideoAcceleratorFactories;
-
 }  // namespace media
 
 namespace content {
 
 // This class creates RTCVideoEncoder instances (each wrapping a
 // media::VideoEncodeAccelerator) on behalf of the WebRTC stack.
 class CONTENT_EXPORT RTCVideoEncoderFactory
     : NON_EXPORTED_BASE(public cricket::WebRtcVideoEncoderFactory) {
  public:
   explicit RTCVideoEncoderFactory(
       const scoped_refptr<media::GpuVideoAcceleratorFactories>& gpu_factories);
   ~RTCVideoEncoderFactory() override;
 
   // cricket::WebRtcVideoEncoderFactory implementation.
   webrtc::VideoEncoder* CreateVideoEncoder(
       webrtc::VideoCodecType type) override;
   const std::vector<VideoCodec>& codecs() const override;
   void DestroyVideoEncoder(webrtc::VideoEncoder* encoder) override;
 
  private:
   const scoped_refptr<media::GpuVideoAcceleratorFactories> gpu_factories_;
 
-  // Codec support list of cricket::WebRtcVideoEncoderFactory::VideoCodec
-  // instances.
+  // List of supported cricket::WebRtcVideoEncoderFactory::VideoCodec.
   std::vector<VideoCodec> codecs_;
 
   DISALLOW_COPY_AND_ASSIGN(RTCVideoEncoderFactory);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_RTC_VIDEO_ENCODER_FACTORY_H_