Add enum value ScaleMethod::kFilterLinear.

webrtc/common_video/libyuv/include/scaler.h

 /*
  *  Copyright (c) 2012 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.
  */
 
 /*
  * Interface to the LibYuv scaling functionality
  */
 
 #ifndef WEBRTC_COMMON_VIDEO_LIBYUV_INCLUDE_SCALER_H_
 #define WEBRTC_COMMON_VIDEO_LIBYUV_INCLUDE_SCALER_H_
 
 #include "webrtc/common_video/include/i420_buffer_pool.h"
 #include "webrtc/common_video/libyuv/include/webrtc_libyuv.h"
 #include "webrtc/typedefs.h"
 #include "webrtc/video_frame.h"
 
 namespace webrtc {
 
 // Supported scaling types
+// Note: Must have the same values as libyuv::FilterMode.

[ossu, 2016/06/03 11:50:32]

So, the problem was it picked the wrong scaling mode due to a mismatch of enums?
Sounds like a dangerous practice. Why isn't ScaleMethod an alias for
libyuv::FilterMode if they need to be the same?

[nisse-webrtc, 2016/06/03 11:54:54]

That's my understanding, yes.
Good question. I would have done that, if it wasn't for my plan to delete this
code very soon (cl https://codereview.webrtc.org/2020593002/).

[ossu, 2016/06/03 12:37:15]

Ah! Then this one-liner really seems like the prudent choice.

 enum ScaleMethod {
   kScalePoint,  // no interpolation
+  kFilterLinear,
   kScaleBilinear,
   kScaleBox
 };
 
 class Scaler {
  public:
   Scaler();
   ~Scaler();
 
   // Set interpolation properties:
@@ skipping 22 matching lines @@
   int           src_height_;
   int           dst_width_;
   int           dst_height_;
   bool          set_;
   I420BufferPool buffer_pool_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_COMMON_VIDEO_LIBYUV_INCLUDE_SCALER_H_