Implement value forward constructor.

So, older constructors taking const T& or T&& is removed.

BUG=784732
TEST=Ran trybot.

Change-Id: I806b1880bf3bd2bd25da764f7592299a1a742366
Reviewed-on: https://chromium-review.googlesource.com/856380
Commit-Queue: Hidehiko Abe <hidehiko@chromium.org>
Reviewed-by: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#538032}

CrOS-Libchrome-Original-Commit: 14f92bee690d0b1884864db08f3e7f03abc85c00
3 files changed
tree: f9eb4bceaf44e01cc4a5fd2832f36d65a9b9852f
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/