Componentize EncryptedMediaMessageFilter and rename it CdmMessageFilter.

content/content_common.gypi

 # Copyright (c) 2012 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.
 
 {
   'dependencies': [
     '../base/base.gyp:base',
     '../components/tracing.gyp:tracing',
     '../gpu/command_buffer/command_buffer.gyp:gles2_utils',
     '../net/net.gyp:net',
@@ skipping 319 matching lines @@
     'common/java_bridge_messages.h',
     'common/mac/attributed_string_coder.h',
     'common/mac/attributed_string_coder.mm',
     'common/mac/font_descriptor.h',
     'common/mac/font_descriptor.mm',
     'common/mac/font_loader.h',
     'common/mac/font_loader.mm',
     'common/media/audio_messages.h',
     'common/media/cdm_messages.h',
     'common/media/cdm_messages_enums.h',
+    'common/media/encrypted_media_messages_android.h',
     'common/media/media_param_traits.cc',
     'common/media/media_param_traits.h',
     'common/media/media_player_messages_android.h',
     'common/media/media_player_messages_enums_android.h',
     'common/media/media_stream_messages.h',
     'common/media/media_stream_options.cc',
     'common/media/media_stream_options.h',
     'common/media/media_stream_track_metrics_host_messages.h',
     'common/media/midi_messages.h',
     'common/media/video_capture.h',
@@ skipping 408 matching lines @@
         'common/sandbox_linux/bpf_renderer_policy_linux.cc',
         'common/sandbox_linux/bpf_renderer_policy_linux.h',
         'common/sandbox_linux/sandbox_bpf_base_policy_linux.cc',
         'common/sandbox_linux/sandbox_bpf_base_policy_linux.h',
       ],
     }, {
       'defines': ['USE_SECCOMP_BPF'],
     }],
   ],
 }