Tentatively turn on WebMediaPlayerMS by default.

content/renderer/render_view_impl.cc

Index: content/renderer/render_view_impl.cc
===================================================================
--- content/renderer/render_view_impl.cc	(revision 161122)
+++ content/renderer/render_view_impl.cc	(working copy)
@@ -2649,7 +2649,7 @@
   if (!media_player) {
     // TODO(wjia): when all patches related to WebMediaPlayerMS have been
     // landed, remove the switch. Refer to crbug.com/142988.
-    if (cmd_line->HasSwitch(switches::kEnableWebMediaPlayerMS)) {
+    if (!cmd_line->HasSwitch(switches::kDisableWebMediaPlayerMS)) {
       EnsureMediaStreamImpl();

[piman, 2012/10/10 22:26:43]

So, when I originally reviewed this, one of my concern is that this call may be
heavy (creating threads etc.), yet you're paying for it whether or not you will
be creating a WebMediaPlayerMS.
Could it be possible to extract whatever you need for just querying
IsMediaStream(url) so that we don't have to pay that cost?

[wjia(left Chromium), 2012/10/10 23:15:12]

yeah, you are right. I added a static function in MediaStreamImpl to remove the
overhead of creating an instance.

       if (media_stream_impl_ && media_stream_impl_->IsMediaStream(url)) {
         return new webkit_media::WebMediaPlayerMS(