Reland "Android notification: Introduce ChromeNotification/PendingIntentProvider."

This CL relands commit 1b5f509ea5d7043572f7fa6950863f54c4fd1740,
reverted in f8914c8150d9da36b057ec05358943d90456b2d8.

TBR=dtrainor@chromium.org, peter@chromium.org

Bug: 898269
Change-Id: Ide9c54dfb47f2468276577c9187657927f66333b
Reviewed-on: https://chromium-review.googlesource.com/c/1379188
Reviewed-by: Xing Liu <xingliu@chromium.org>
Commit-Queue: Xing Liu <xingliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#616876}
4 files changed