Remove the 'double' methods from blink::TimerBase

Remove the methods in blink::TimerBase that either take or return
a time delta as a double. These methods are mostly unused - a few calls
to StartOneShot and NextFireInterval, and it should be preferable for
new code to use the TimeDelta methods. The non-Delta-suffixed names are
kept - i.e they take on the name of their removed equivalent where
applicable.

The few users of StartOneShot(double, ...) are open-coded instead, and
uses of other methods are adjusted as needed.

The unit tests for Timer is overhauled to use TimeTicks and TimeDelta
throughout.

Bug: 763980
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I47c0449a9ea68e6e984c371e19f03f747bb5b1e0
Reviewed-on: https://chromium-review.googlesource.com/1131131
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574127}
10 files changed