Add visibility for rtc_vp9_profile

This is necessary to access profiles from Chrome side.

Bug: webrtc:7925
Change-Id: I27d187afb56da715caf9f2ac8a6942778853542c
Reviewed-on: https://webrtc-review.googlesource.com/c/113100
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Emircan Uysaler <emircan@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25925}
diff --git a/media/BUILD.gn b/media/BUILD.gn
index f54bb73..84fd610 100644
--- a/media/BUILD.gn
+++ b/media/BUILD.gn
@@ -55,6 +55,7 @@
 }
 
 rtc_source_set("rtc_vp9_profile") {
+  visibility = [ "*" ]
   sources = [
     "base/vp9_profile.cc",
     "base/vp9_profile.h",