Looks like we could try to remove RPC Protobuf code and the demuxer from the Android build to make the regression smaller. I'll take a stab at it next week.

It's unclear to me from the CL description if this change is something needed for M61. If it was just a step along the way to a feature, and doesn't add functionality by itself, I'd like to revert it on the M61 branch (it slipped in right before branch cut).

I'm okay with reverting it on the branch, it's behind the flag anyway.
I have a long-term fix removing ~70Kb here: https://chromium-review.googlesource.com/c/584019

+amineer - Okay if we revert this on M61 branch?
Note: not reverting on master, so there's no existing commit to merge. 

Merged to branch as:
 https://chromium.googlesource.com/chromium/src/+/312663539c586249c35f9f4a9ee94162fb860a57

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/312663539c586249c35f9f4a9ee94162fb860a57

commit 312663539c586249c35f9f4a9ee94162fb860a57
Author: Andrew Grieve <agrieve@chromium.org>
Date: Fri Jul 28 15:34:52 2017

Revert "[RemotePlayback] Add media source info to the RemotePlayback availability url"

This reverts commit 09fa66e1baaa95d069bbd6620670311ae8aa4dc5.

TBR=agrieve@chromium.org

(cherry picked from commit ec724bb577b376824afcfe1e71e4c06a97357d9f)

Bug:  747420 
Change-Id: I193769115a2304ebf5c25c1c82fa57bcad96838b
Reviewed-on: https://chromium-review.googlesource.com/591928
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/branch-heads/3163@{#98}
Cr-Branched-From: ff259bab28b35d242e10186cd63af7ed404fae0d-refs/heads/master@{#488528}
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/content/renderer/media/webmediaplayer_ms_unittest.cc
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/media/base/media_observer.h
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/media/base/renderer_factory_selector.cc
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/media/blink/webmediaplayer_impl.cc
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/media/blink/webmediaplayer_impl.h
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/media/blink/webmediaplayer_impl_unittest.cc
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/media/media_options.gni
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/media/remoting/renderer_controller.cc
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/media/remoting/renderer_controller.h
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/media/remoting/renderer_controller_unittest.cc
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/third_party/WebKit/Source/core/html/HTMLMediaElement.h
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.cpp
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.h
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/third_party/WebKit/Source/modules/remoteplayback/RemotePlaybackTest.cpp
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/third_party/WebKit/public/platform/WebMediaPlayerClient.h
[modify] https://crrev.com/312663539c586249c35f9f4a9ee94162fb860a57/third_party/WebKit/public/platform/modules/remoteplayback/WebRemotePlaybackClient.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/45929e1d192f1a68acc2d88c4f13c45232c5043a

commit 45929e1d192f1a68acc2d88c4f13c45232c5043a
Author: Anton Vayvod <avayvod@google.com>
Date: Tue Aug 08 01:23:18 2017

Disable Media Remoting RPC on Android

Bug:  747420 
Test: Linux and Android builds succeed.
Change-Id: Iefdd3e65783a44410936053f66fff4e58cbdab99
Reviewed-on: https://chromium-review.googlesource.com/584019
Commit-Queue: Anton Vayvod <avayvod@chromium.org>
Reviewed-by: Thomas Guilbert <tguilbert@chromium.org>
Reviewed-by: Yuri Wiitala <miu@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#492491}
[modify] https://crrev.com/45929e1d192f1a68acc2d88c4f13c45232c5043a/media/BUILD.gn
[modify] https://crrev.com/45929e1d192f1a68acc2d88c4f13c45232c5043a/media/media_options.gni
[modify] https://crrev.com/45929e1d192f1a68acc2d88c4f13c45232c5043a/media/remoting/BUILD.gn
[modify] https://crrev.com/45929e1d192f1a68acc2d88c4f13c45232c5043a/media/remoting/courier_renderer_factory.cc
[modify] https://crrev.com/45929e1d192f1a68acc2d88c4f13c45232c5043a/media/remoting/fake_remoter.cc
[modify] https://crrev.com/45929e1d192f1a68acc2d88c4f13c45232c5043a/media/remoting/renderer_controller.cc
[modify] https://crrev.com/45929e1d192f1a68acc2d88c4f13c45232c5043a/media/remoting/renderer_controller.h
[modify] https://crrev.com/45929e1d192f1a68acc2d88c4f13c45232c5043a/media/remoting/shared_session.cc
[modify] https://crrev.com/45929e1d192f1a68acc2d88c4f13c45232c5043a/media/remoting/shared_session.h

Graph shows a 60 kb reduction: https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDgmd6yqgoM.

Thanks for following up on this!