Make base::WriteFile use mode 0666 instead of 0640.

Temporarily revert base::WriteFile to the behavior in older
revision of libchrome until we sort out the expected file
permissions at all call sites of base::WriteFile in Chrome
OS code (crbug.com/412057).

This is benchan@chromium.org's
base-334380-revert-writefile-permissions.patch from Chrome
OS. The original commit was
https://chromium-review.googlesource.com/216584.

Bug: 22317122
Change-Id: Ia86ef66122b6cf148bad56d13ef82624e1db8a5b
1 file changed