Media Remoting: Add browser tests.

chrome/test/BUILD.gn

Index: chrome/test/BUILD.gn
diff --git a/chrome/test/BUILD.gn b/chrome/test/BUILD.gn
index 182dcd7dcb0b7f0d218a23772ba798204dcc850d..2320d6e35465db06d61744908d7088a2d36a9ef7 100644
--- a/chrome/test/BUILD.gn
+++ b/chrome/test/BUILD.gn
@@ -23,6 +23,8 @@ import("//testing/test.gni")
 import("//ui/base/ui_features.gni")
 import("//v8/gni/v8.gni")
 
+import("//extensions/common/api/schema.gni")
+
 if (is_android) {
   import("//build/config/android/rules.gni")
 }
@@ -1299,6 +1301,7 @@ test("browser_tests") {
 
     enable_multidex = true
   } else {  # Not Android.
+    defines += [ "ENABLE_MEDIA_ROUTER=1" ]
     sources += [
       # The list of sources which is only used by chrome browser tests on
       # desktop platforms.
@@ -1437,6 +1440,7 @@ test("browser_tests") {
       "../browser/extensions/api/management/management_browsertest.cc",
       "../browser/extensions/api/media_galleries/media_galleries_apitest.cc",
       "../browser/extensions/api/media_galleries/media_galleries_watch_apitest.cc",
+      "../browser/extensions/api/media_remoting/media_remoting_browser_test.cc",
       "../browser/extensions/api/messaging/native_messaging_apitest.cc",
       "../browser/extensions/api/metrics_private/metrics_apitest.cc",
       "../browser/extensions/api/module/module_apitest.cc",