Add an IPC to return the platform supported key-system names in Android.

components/cdm.gypi

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'cdm_common',
       'type': 'static_library',
       'dependencies': [
@@ skipping 18 matching lines @@
         '../third_party/widevine/cdm/widevine_cdm.gyp:widevine_cdm_version_h',
       ],
       'include_dirs': [
         # Needed by widevine_key_systems.cc.
         '<(SHARED_INTERMEDIATE_DIR)',
       ],
       'sources': [
         'cdm/renderer/widevine_key_systems.cc',
         'cdm/renderer/widevine_key_systems.h',
       ],
+      'conditions': [
+        ['OS == "android"', {
+          'sources': [
+            'cdm/renderer/android_key_systems.cc',
+            'cdm/renderer/android_key_systems.h',
+          ],
+        }],
+      ],
     },
   ],
   'conditions': [
     ['OS == "android"', {
       'targets': [
         {
           'target_name': 'cdm_browser',
           'type': 'static_library',
           'dependencies': [
             'cdm_common',
             '../base/base.gyp:base',
             '../content/content.gyp:content_browser',
             '../content/content.gyp:content_common',
             '../media/media.gyp:media',
           ],
           'sources': [
             'cdm/browser/cdm_message_filter_android.cc',
             'cdm/browser/cdm_message_filter_android.h',
           ],
         },
       ],
     }],
   ],
 }