sandersd@: How do we plumb the CDM via MojoVideoDecoder?  

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2116b727cea4a3aca8d92ab9b0fdb55e9654e940

commit 2116b727cea4a3aca8d92ab9b0fdb55e9654e940
Author: liberato@chromium.org <liberato@chromium.org>
Date: Tue Nov 21 03:26:44 2017

Provide CdmContext to mojo VideoDecoders

This CL provides a CdmContext for encrypted content to the
VideoDecoder instance.  It also extracts the shared code from the
mojo AudioDecoder service, and shares it.

Bug:  760821 
Test: Manual: L3 audio still plays, MCVD gets non-null Cdm
Change-Id: Ib1d088f8c18af367ca6cc0f3edebd7e8ffcea0df
Reviewed-on: https://chromium-review.googlesource.com/776013
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Xiaohan Wang <xhwang@chromium.org>
Reviewed-by: Dan Sanders <sandersd@chromium.org>
Commit-Queue: Frank Liberato <liberato@chromium.org>
Cr-Commit-Position: refs/heads/master@{#518079}
[modify] https://crrev.com/2116b727cea4a3aca8d92ab9b0fdb55e9654e940/media/mojo/clients/mojo_video_decoder.cc
[modify] https://crrev.com/2116b727cea4a3aca8d92ab9b0fdb55e9654e940/media/mojo/interfaces/video_decoder.mojom
[modify] https://crrev.com/2116b727cea4a3aca8d92ab9b0fdb55e9654e940/media/mojo/services/interface_factory_impl.cc
[modify] https://crrev.com/2116b727cea4a3aca8d92ab9b0fdb55e9654e940/media/mojo/services/mojo_video_decoder_service.cc
[modify] https://crrev.com/2116b727cea4a3aca8d92ab9b0fdb55e9654e940/media/mojo/services/mojo_video_decoder_service.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/204e8b07ef99c99c19f0176f5eea0ecefec926d0

commit 204e8b07ef99c99c19f0176f5eea0ecefec926d0
Author: liberato@chromium.org <liberato@chromium.org>
Date: Tue Nov 21 22:28:54 2017

Enable Cdm use in MediaCodecVideoDecoder.

This CL causes MCVD to use the Cdm that's provided for secure
content.  It requests a secure codec when needed, and a secure
output surface.

Bug:  760821 
Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I11ac076d729913b0c8b76d9f5133af8ea3f11c09
Reviewed-on: https://chromium-review.googlesource.com/779620
Commit-Queue: Frank Liberato <liberato@chromium.org>
Reviewed-by: Chris Watkins <watk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#518416}
[modify] https://crrev.com/204e8b07ef99c99c19f0176f5eea0ecefec926d0/media/base/android/BUILD.gn
[modify] https://crrev.com/204e8b07ef99c99c19f0176f5eea0ecefec926d0/media/base/android/media_drm_bridge.h
[modify] https://crrev.com/204e8b07ef99c99c19f0176f5eea0ecefec926d0/media/base/android/media_drm_bridge_cdm_context.h
[rename] https://crrev.com/204e8b07ef99c99c19f0176f5eea0ecefec926d0/media/base/android/media_drm_bridge_cdm_context_impl.cc
[add] https://crrev.com/204e8b07ef99c99c19f0176f5eea0ecefec926d0/media/base/android/media_drm_bridge_cdm_context_impl.h
[add] https://crrev.com/204e8b07ef99c99c19f0176f5eea0ecefec926d0/media/base/android/mock_media_drm_bridge_cdm_context.cc
[add] https://crrev.com/204e8b07ef99c99c19f0176f5eea0ecefec926d0/media/base/android/mock_media_drm_bridge_cdm_context.h
[modify] https://crrev.com/204e8b07ef99c99c19f0176f5eea0ecefec926d0/media/gpu/android/fake_codec_allocator.cc
[modify] https://crrev.com/204e8b07ef99c99c19f0176f5eea0ecefec926d0/media/gpu/android/fake_codec_allocator.h
[modify] https://crrev.com/204e8b07ef99c99c19f0176f5eea0ecefec926d0/media/gpu/android/media_codec_video_decoder.cc
[modify] https://crrev.com/204e8b07ef99c99c19f0176f5eea0ecefec926d0/media/gpu/android/media_codec_video_decoder.h
[modify] https://crrev.com/204e8b07ef99c99c19f0176f5eea0ecefec926d0/media/gpu/android/media_codec_video_decoder_unittest.cc