Move EME key system knowledge from content/ to chrome/.

chrome/renderer/media/chrome_key_systems.h

Index: chrome/renderer/media/chrome_key_systems.h
diff --git a/chrome/renderer/media/chrome_key_systems.h b/chrome/renderer/media/chrome_key_systems.h
new file mode 100644
index 0000000000000000000000000000000000000000..3409038b44311e1f6f2731ce48b5fe0e7c308d31
--- /dev/null
+++ b/chrome/renderer/media/chrome_key_systems.h
@@ -0,0 +1,12 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_RENDERER_MEDIA_CHROME_KEY_SYSTEMS_H_
+#define CHROME_RENDERER_MEDIA_CHROME_KEY_SYSTEMS_H_
+
+#include "content/public/renderer/key_system_info.h"
+
+void AddChromeKeySystems(std::vector<content::KeySystemInfo>* key_systems_info);
+
+#endif  // CHROME_RENDERER_MEDIA_CHROME_KEY_SYSTEMS_H_