WebContentsVideoCapture Cleanup: Gut-out dead code, and tighten BUILDs.

content/browser/renderer_host/media/video_capture_manager.cc

Index: content/browser/renderer_host/media/video_capture_manager.cc
diff --git a/content/browser/renderer_host/media/video_capture_manager.cc b/content/browser/renderer_host/media/video_capture_manager.cc
index a316e94b61e94e5532126a83af2c85dbc3036870..a75d86e28193333ea163cc881ffa3c0dc9adfae5 100644
--- a/content/browser/renderer_host/media/video_capture_manager.cc
+++ b/content/browser/renderer_host/media/video_capture_manager.cc
@@ -614,7 +614,9 @@ VideoCaptureManager::DoStartTabCaptureOnDeviceThread(
   DCHECK(IsOnDeviceThread());
 
   std::unique_ptr<VideoCaptureDevice> video_capture_device;
+#if defined(OS_LINUX) || defined(OS_MACOSX) || defined(OS_WIN)
   video_capture_device = WebContentsVideoCaptureDevice::Create(id);
+#endif
 
   if (!video_capture_device) {
     device_client->OnError(FROM_HERE, "Could not create capture device");
@@ -642,6 +644,7 @@ VideoCaptureManager::DoStartDesktopCaptureOnDeviceThread(
   }
 
   if (desktop_id.type == DesktopMediaID::TYPE_WEB_CONTENTS) {
+#if defined(OS_LINUX) || defined(OS_MACOSX) || defined(OS_WIN)
     video_capture_device = WebContentsVideoCaptureDevice::Create(id);
     IncrementDesktopCaptureCounter(TAB_VIDEO_CAPTURER_CREATED);
     if (desktop_id.audio_share) {
@@ -649,6 +652,7 @@ VideoCaptureManager::DoStartDesktopCaptureOnDeviceThread(
     } else {
       IncrementDesktopCaptureCounter(TAB_VIDEO_CAPTURER_CREATED_WITHOUT_AUDIO);
     }
+#endif
   } else {
 #if defined(OS_ANDROID)
     video_capture_device = base::MakeUnique<ScreenCaptureDeviceAndroid>();