Add a new GetInstance() method for remaining files with singleton classes under chrome/browser.

chrome/browser/dom_ui/mediaplayer_ui.cc

Index: chrome/browser/dom_ui/mediaplayer_ui.cc
diff --git a/chrome/browser/dom_ui/mediaplayer_ui.cc b/chrome/browser/dom_ui/mediaplayer_ui.cc
index 2fb141c6bc9df405c2fd4e384d0e3451d1f67d3e..3119e534ad28903d1fae31e87aa1f5564f4de978 100644
--- a/chrome/browser/dom_ui/mediaplayer_ui.cc
+++ b/chrome/browser/dom_ui/mediaplayer_ui.cc
@@ -355,6 +355,11 @@ DISABLE_RUNNABLE_METHOD_REFCOUNT(MediaPlayer);
 MediaPlayer::~MediaPlayer() {
 }
 
+// static
+MediaPlayer* MediaPlayer::Get() {
+  return Singleton<MediaPlayer>::get();
+}
+
 void MediaPlayer::EnqueueMediaURL(const GURL& url, Browser* creator) {
   if (!Enabled()) {
     return;