Revert of [mojo-bindings] Use Watch API instead of MessagePumpMojo (patchset #10 id:180001 of https://codereview.chromium.org/1759783003/ )

Reason for revert:
Breaks iOS GN which is apparently a tree closer despite having no CQ coverage

Original issue's description:
> [mojo-bindings] Use Watch API instead of MessagePumpMojo
>
> This removes the C++ bindings dependency on MessagePumpMojo,
> consuming the new Watch API instead.
>
> For convenience a new mojo::Watcher is added to the public
> Mojo C++ API library, and this is used by Connector.
>
> BUG=590495
> R=yzshen@chromium.org
> TBR=blundell@chromium.org for rename affecting components/message_port.gypi
> TBR=jam@chromium.org - added a missing header to new url tests
>
> Committed: https://crrev.com/d06373e7cd8b4ad725ed5c64c958f2de13585add
> Cr-Commit-Position: refs/heads/master@{#379402}

TBR=jam@chromium.org,yzshen@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=590495

Review URL: https://codereview.chromium.org/1768443004

Cr-Commit-Position: refs/heads/master@{#379406}


CrOS-Libchrome-Original-Commit: 258f8f50d607b2b585bb18631efbe75fb5f01913
10 files changed
tree: 5f5e6e98fa8630583dfb2374f89e31f0b1423cba
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/