Add unit test for stand-alone denoiser and fixed some bugs.

webrtc/modules/video_processing/video_denoiser.h

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_VIDEO_PROCESSING_VIDEO_DENOISER_H_
 #define WEBRTC_MODULES_VIDEO_PROCESSING_VIDEO_DENOISER_H_
 
 #include "webrtc/modules/video_processing/util/denoiser_filter.h"
 #include "webrtc/modules/video_processing/util/skin_detection.h"
 
 namespace webrtc {
 
 class VideoDenoiser {
  public:
-  VideoDenoiser();
+  explicit VideoDenoiser(bool runtime_cpu_detection);
   void DenoiseFrame(const VideoFrame& frame, VideoFrame* denoised_frame);
 
  private:
   void TrailingReduction(int mb_rows,
                          int mb_cols,
                          const uint8_t* y_src,
                          int stride_y,
                          uint8_t* y_dst);
   int width_;
   int height_;
   rtc::scoped_ptr<DenoiseMetrics[]> metrics_;
   rtc::scoped_ptr<DenoiserFilter> filter_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_VIDEO_PROCESSING_VIDEO_DENOISER_H_