Fix V4L2VideoEncodeAccelerator is not enabled in GN build

media/gpu/ipc/service/gpu_video_encode_accelerator.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 MEDIA_GPU_IPC_SERVICE_GPU_VIDEO_ENCODE_ACCELERATOR_H_
 #define MEDIA_GPU_IPC_SERVICE_GPU_VIDEO_ENCODE_ACCELERATOR_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 62 matching lines @@
   static gpu::VideoEncodeAcceleratorSupportedProfiles GetSupportedProfiles(
       const gpu::GpuPreferences& gpu_preferences);
 
  private:
   typedef std::unique_ptr<VideoEncodeAccelerator> (*CreateVEAFp)();
 
   // Return a set of VEA Create function pointers applicable to the current
   // platform.
   static std::vector<CreateVEAFp> CreateVEAFps(
       const gpu::GpuPreferences& gpu_preferences);
-#if defined(OS_CHROMEOS) && defined(USE_V4L2_CODEC)
+#if defined(OS_CHROMEOS) && (defined(ARCH_CPU_ARMEL) || \
+                             (defined(USE_OZONE) && defined(USE_V4L2_CODEC)))

[wuchengli, 2016/07/12 11:39:51]

Why do we need ozone? https://codereview.chromium.org/834113004 does the same. I
don't understand the relationship between having ozone and having v4l2 devices.
Don't all x86 have ozone?

This is not related to this CL. So if we don't need ozone, we can remove it in
another CL.

[ilja, 2016/07/12 21:25:02]

All shipping boards except for tegra have ozone right now. But I think generic
builds might not have it. Of course that config is becoming less and less
relevant these days.

[wuchengli, 2016/07/13 02:24:10]

I looked at the git history and old chromium issues. I'm sure USE_OZONE is not
needed here.

[henryhsu, 2016/07/13 03:29:59]

will remove in another cl

   static std::unique_ptr<VideoEncodeAccelerator> CreateV4L2VEA();
 #endif
 #if defined(OS_CHROMEOS) && defined(ARCH_CPU_X86_FAMILY)
   static std::unique_ptr<VideoEncodeAccelerator> CreateVaapiVEA();
 #endif
 #if defined(OS_ANDROID) && defined(ENABLE_WEBRTC)
   static std::unique_ptr<VideoEncodeAccelerator> CreateAndroidVEA();
 #endif
 #if defined(OS_MACOSX)
   static std::unique_ptr<VideoEncodeAccelerator> CreateVTVEA();
@@ skipping 34 matching lines @@
 
   // Weak pointer for VideoFrames that refer back to |this|.
   base::WeakPtrFactory<GpuVideoEncodeAccelerator> weak_this_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuVideoEncodeAccelerator);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_GPU_IPC_SERVICE_GPU_VIDEO_ENCODE_ACCELERATOR_H_