Add placeholder chrome://media-internals page.

chrome/browser/ui/webui/chrome_web_ui_factory.cc

Index: chrome/browser/ui/webui/chrome_web_ui_factory.cc
diff --git a/chrome/browser/ui/webui/chrome_web_ui_factory.cc b/chrome/browser/ui/webui/chrome_web_ui_factory.cc
index 56060bc5061970ba81be549e0545b355acc2cf2e..45a1f4bec6835ca1fd99ad821024a13e8f33d5bb 100644
--- a/chrome/browser/ui/webui/chrome_web_ui_factory.cc
+++ b/chrome/browser/ui/webui/chrome_web_ui_factory.cc
@@ -22,6 +22,7 @@
 #include "chrome/browser/ui/webui/history2_ui.h"
 #include "chrome/browser/ui/webui/history_ui.h"
 #include "chrome/browser/ui/webui/html_dialog_ui.h"
+#include "chrome/browser/ui/webui/media_internals_ui.h"
 #include "chrome/browser/ui/webui/net_internals_ui.h"
 #include "chrome/browser/ui/webui/ntp/new_tab_ui.h"
 #include "chrome/browser/ui/webui/options/options_ui.h"
@@ -160,6 +161,8 @@ static WebUIFactoryFunction GetWebUIFactoryFunction(Profile* profile,
 #endif
   if (url.host() == chrome::kChromeUIGpuInternalsHost)
     return &NewWebUI<GpuInternalsUI>;
+  if (url.host() == chrome::kChromeUIMediaInternalsHost)
+    return &NewWebUI<MediaInternalsUI>;
   if (url.host() == chrome::kChromeUINetInternalsHost)
     return &NewWebUI<NetInternalsUI>;
   if (url.host() == chrome::kChromeUIPluginsHost)