[Chromecast] Enable browser media tests to work on internal builds

chromecast/browser/BUILD.gn

Index: chromecast/browser/BUILD.gn
diff --git a/chromecast/browser/BUILD.gn b/chromecast/browser/BUILD.gn
index 6e92f1abb18ed280b451604dc6bf67c5ee5ce297..d801a9673d8dd06d644272daaefdda7fdf32cbb0 100644
--- a/chromecast/browser/BUILD.gn
+++ b/chromecast/browser/BUILD.gn
@@ -145,9 +145,14 @@ source_set("test_support") {
   sources = [
     "test/chromecast_browser_test.cc",
     "test/chromecast_browser_test.h",
+    "test/chromecast_browser_test_helper.h",
     "test/chromecast_browser_test_runner.cc",
   ]
 
+  if (chromecast_branding == "public") {
+    sources += [ "test/chromecast_browser_test_helper_default.cc" ]
+  }
+
   public_deps = [
     ":browser",
     "//chromecast:cast_shell_common",
@@ -190,6 +195,7 @@ test("cast_shell_browser_test") {
   # TODO(slan): Find a better way to do this.
   if (chromecast_branding != "public") {
     deps += [ "//chromecast/internal:cast_shell_internal" ]
+    deps += [ "//chromecast/internal/shell:cast_shell_browser_test_helper_internal" ]
   }
 
   if (chromecast_branding == "public") {