Remove Media runtime flag (status=stable) for chromium

BUG=402536

Review URL: https://codereview.chromium.org/590083002

Cr-Commit-Position: refs/heads/master@{#296674}

content/renderer/render_thread_impl.cc

@@ -913,7 +913,6 @@ void RenderThreadImpl::EnsureWebKitInitialized() {
   SetRuntimeFeaturesDefaultsAndUpdateFromArgs(command_line);
 
   if (!media::IsMediaLibraryInitialized()) {
-    WebRuntimeFeatures::enableMediaPlayer(false);
     WebRuntimeFeatures::enableWebAudio(false);
   }