Making the Mojo Channel Messages legacy mode dynamic.

The mojo::edk::Channel::Message class uses a compile flag to determine
whether to use the legacy or normal mode (legacy mode is used to keep
backward compatibility between Arc++ and ChromeOS).
Making that flag dynamically set on the embedder so that the default is
now normal mode on Android. This is going to be used for adding
Parcelable support on mojo Android (where we'll need the normal
Message's header to include the parcelables).

BUG=699311

Review-Url: https://codereview.chromium.org/2749853003
Cr-Commit-Position: refs/heads/master@{#457549}


CrOS-Libchrome-Original-Commit: f2be81a465a7b2ef07b3667f83de1009206acace
4 files changed
tree: a6d7863814e24593f3f11f3d2a9e4069e4b56be1
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/