Pass camera facing info to audio client

media/base/BUILD.gn

Index: media/base/BUILD.gn
diff --git a/media/base/BUILD.gn b/media/base/BUILD.gn
index 098adc683b74868a9e73309d8fb24f8279d64a6f..b629cadad5629ba4def0938cbf5fc51b154a2dd6 100644
--- a/media/base/BUILD.gn
+++ b/media/base/BUILD.gn
@@ -264,6 +264,7 @@ target(link_target_type, "base") {
   allow_circular_includes_from = []
   defines = []
   public_deps = [
+    "//media/base:video_facing",
     "//ppapi/features",
     "//ui/gfx:color_space",
   ]
@@ -337,6 +338,19 @@ target(link_target_type, "base") {
   }
 }
 
+source_set("video_facing") {
+  visibility = [
+    "//chromeos",
+    "//content/browser",
+    "//content/public/common:common_sources",
+    "//media/base",
+    "//media/capture",
+  ]
+  sources = [
+    "video_facing.h",
+  ]
+}
+
 static_library("test_support") {
   testonly = true
   sources = [