Make IsSyncRequested false by default

Before this CL, the value of IsSyncRequested was essentially undefined
while Sync was disabled: It was true by default, but false if the user
had previously enabled Sync and then disabled it again.
This CL resolves the inconsistency by making it false by default.

Bug: 906034
Change-Id: I2ce92f5df5ebb38a34ebde43d471839ad1184961
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1508453
Reviewed-by: Jan Krcal <jkrcal@chromium.org>
Commit-Queue: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#642447}
11 files changed