media: Support MojoMediaApplication in GPU process.

content/browser/BUILD.gn

Index: content/browser/BUILD.gn
diff --git a/content/browser/BUILD.gn b/content/browser/BUILD.gn
index 23dca61865debf74c1bafd5b68b868b9e2299f33..d6c8e24792659de6d255eb6e9d0ea374642fffd0 100644
--- a/content/browser/BUILD.gn
+++ b/content/browser/BUILD.gn
@@ -492,6 +492,10 @@ source_set("browser") {
     deps += [ "//third_party/boringssl" ]
   }
 
+  if (enable_mojo_media != "none") {
+    configs += [ "//media/mojo/services:enable_mojo_media_config" ]
+  }
+
   if (enable_mojo_media == "browser") {
     deps += [ "//media/mojo/services:application" ]
   }