[Media Router] Update Media Router flags post-launch.

chrome/test/media_router/media_router_base_browsertest.cc

Index: chrome/test/media_router/media_router_base_browsertest.cc
diff --git a/chrome/test/media_router/media_router_base_browsertest.cc b/chrome/test/media_router/media_router_base_browsertest.cc
index 6ed5e9e1d9927a6ddd1257f995d68fad9fce85df..c482015ebbd543f3f76ec7f85b94cc2ca00e4156 100644
--- a/chrome/test/media_router/media_router_base_browsertest.cc
+++ b/chrome/test/media_router/media_router_base_browsertest.cc
@@ -33,10 +33,7 @@ namespace media_router {
 MediaRouterBaseBrowserTest::MediaRouterBaseBrowserTest()
     : extension_load_event_(base::WaitableEvent::ResetPolicy::AUTOMATIC,
                             base::WaitableEvent::InitialState::NOT_SIGNALED),
-      extension_host_created_(false),
-      feature_override_(extensions::FeatureSwitch::media_router(), true) {
-  base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
-      switches::kEnableExperimentalWebPlatformFeatures, "Presentation");
+      extension_host_created_(false) {
 }
 
 MediaRouterBaseBrowserTest::~MediaRouterBaseBrowserTest() {