gn: Hide modules/video_capture:video_capture_internal_impl behind an arg

R=andresp@webrtc.org, brettw@chromium.org, kjellander@webrtc.org, pbos@webrtc.org, brettw

Review URL: https://webrtc-codereview.appspot.com/30479004

Patch from Cem Kocagil <ckocagil@chromium.org>.

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@7274 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/modules/video_capture/BUILD.gn b/modules/video_capture/BUILD.gn
index 773708b..b9f3d2f 100644
--- a/modules/video_capture/BUILD.gn
+++ b/modules/video_capture/BUILD.gn
@@ -100,7 +100,10 @@
       "QTKit.framework",
     ]
   }
-  if (is_win) {
+  # winsdk_samples isn't pulled into Chromium, so it is disabled for Chromium
+  # builds. This is not a problem since the internal video capture
+  # implementation should not be used in chrome - issue 3831.
+  if (is_win && !build_with_chromium) {
     sources = [
       "windows/device_info_ds.cc",
       "windows/device_info_ds.h",