Clipboard: Create *NoCommit write functions

All write functions should be *NoCommit, to allow for more customizable writes
of multiple data types to the system clipboard in the future.

Bug: 941085
Change-Id: Ie1c462f7ab4aca614285272ed78691f224cbba2c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1529919
Commit-Queue: Darwin Huang <huangdarwin@chromium.org>
Commit-Queue: Victor Costan <pwnall@chromium.org>
Reviewed-by: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641967}
2 files changed