[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}

Review URL: https://codereview.chromium.org/1759783003

Cr-Commit-Position: refs/heads/master@{#379463}


CrOS-Libchrome-Original-Commit: 2cdb2f677c68f06b3bc54cd40f000ab961a09bbb
10 files changed
tree: 6e69cfb1ec4bf3123d5a652a8760377533d9c038
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/