Chromecast buildfix: content::KeySystemsInfo moved to media namespace.

chromecast/renderer/key_systems_cast_simple.cc

 // Copyright 2014 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.
 
 #include "chromecast/renderer/key_systems_cast.h"
 
 namespace chromecast {
 namespace shell {
 
 void AddChromecastPlatformKeySystems(
-    std::vector<content::KeySystemInfo>* key_systems_info) {
+    std::vector< ::media::KeySystemInfo>* key_systems_info) {
   // Intentional no-op for public build.
 }
 
 }  // namespace shell
 }  // namespace chromecast