Move enable_webrtc to a buildflag header.

content/browser/gpu/gpu_data_manager_impl_private.cc

Index: content/browser/gpu/gpu_data_manager_impl_private.cc
diff --git a/content/browser/gpu/gpu_data_manager_impl_private.cc b/content/browser/gpu/gpu_data_manager_impl_private.cc
index 0414f6c311072b1baa3d6ae9176e1ab0f6c7f3d4..44bcf28b88b13008533d2c56f83d6c93df21c898 100644
--- a/content/browser/gpu/gpu_data_manager_impl_private.cc
+++ b/content/browser/gpu/gpu_data_manager_impl_private.cc
@@ -689,7 +689,7 @@ void GpuDataManagerImplPrivate::AppendRendererCommandLine(
 
   if (ShouldDisableAcceleratedVideoDecode(command_line))
     command_line->AppendSwitch(switches::kDisableAcceleratedVideoDecode);
-#if defined(ENABLE_WEBRTC)
+#if BUILDFLAG(ENABLE_WEBRTC)

[sky, 2016/11/21 22:36:05]

How come you don't include media/media_features in all files that use
ENABLE_WEBRTC?

[brettw, 2016/11/21 23:18:45]

I missed this one (it's included in several "popular" headers which is why I
guess it works). Most of the ones that you don't see the addition in already
have it.

   if (IsFeatureBlacklisted(gpu::GPU_FEATURE_TYPE_ACCELERATED_VIDEO_ENCODE) &&
       !command_line->HasSwitch(switches::kDisableWebRtcHWEncoding))
     command_line->AppendSwitch(switches::kDisableWebRtcHWEncoding);
@@ -772,7 +772,7 @@ void GpuDataManagerImplPrivate::AppendGpuCommandLine(
   }
 #endif
 
-#if defined(ENABLE_WEBRTC)
+#if BUILDFLAG(ENABLE_WEBRTC)
   if (IsFeatureBlacklisted(gpu::GPU_FEATURE_TYPE_ACCELERATED_VIDEO_ENCODE) &&
       !command_line->HasSwitch(switches::kDisableWebRtcHWEncoding)) {
     if (gpu_preferences) {