Move enable_webrtc to a buildflag header.

content/shell/renderer/layout_test/test_media_stream_renderer_factory.cc

Index: content/shell/renderer/layout_test/test_media_stream_renderer_factory.cc
diff --git a/content/shell/renderer/layout_test/test_media_stream_renderer_factory.cc b/content/shell/renderer/layout_test/test_media_stream_renderer_factory.cc
index 4599977451694f263a6a0fba5a340896526aa932..73300eeaca28d47250b7ba2b576d41d2df0c6576 100644
--- a/content/shell/renderer/layout_test/test_media_stream_renderer_factory.cc
+++ b/content/shell/renderer/layout_test/test_media_stream_renderer_factory.cc
@@ -5,6 +5,7 @@
 #include "content/shell/renderer/layout_test/test_media_stream_renderer_factory.h"
 
 #include "content/shell/renderer/layout_test/test_media_stream_video_renderer.h"
+#include "media/media_features.h"
 #include "third_party/WebKit/public/platform/WebMediaStream.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
 #include "third_party/WebKit/public/web/WebMediaStreamRegistry.h"
@@ -19,7 +20,7 @@ static const int kVideoCaptureHeight = 288;
 static const int kVideoCaptureFrameDurationMs = 33;
 
 bool IsMockMediaStreamWithVideo(const WebMediaStream& web_stream) {
-#if ENABLE_WEBRTC
+#if BUILDFLAG(ENABLE_WEBRTC)
   if (web_stream.isNull())
     return false;
   WebVector<WebMediaStreamTrack> video_tracks;