Adds initial key systems support for Chromecast.

chromecast/shell/renderer/key_systems_cast_simple.cc

Index: chromecast/shell/renderer/key_systems_cast_simple.cc
diff --git a/chromecast/android/platform_jni_loader_stub.cc b/chromecast/shell/renderer/key_systems_cast_simple.cc
similarity index 57%
copy from chromecast/android/platform_jni_loader_stub.cc
copy to chromecast/shell/renderer/key_systems_cast_simple.cc
index 0f8d814b0f99359a4fb21b9c350870b9fd971d3d..752669f07a76c3ddd7cd814a5aa7bb337e1f4051 100644
--- a/chromecast/android/platform_jni_loader_stub.cc
+++ b/chromecast/shell/renderer/key_systems_cast_simple.cc
@@ -2,15 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chromecast/android/platform_jni_loader.h"
+#include "chromecast/shell/renderer/key_systems_cast.h"
 
 namespace chromecast {
-namespace android {
+namespace shell {
 
-bool PlatformRegisterJni(JNIEnv* env) {
+void AddChromecastPlatformKeySystems(
+    std::vector<content::KeySystemInfo>* key_systems_info) {
   // Intentional no-op for public build.
-  return true;
 }
 
-}  // namespace android
+}  // namespace shell
 }  // namespace chromecast