Change dont_embed_build_metadata default to 1 except for Official build and fix some unittests.
FieldTrialTest.DisableProbability was using Time::NowFromSystemTime - 1 year to generate a date before the build time. Instead use GetBuildTime - 1 year.
TransportSecurityState::IsBuildTimely is using GetBuildTime to determine if the build is older than 10 weeks. Disable this and return a default value if DONT_EMBED_BUILD_METADATA is defined (i.e. The build time is invalid) and we're not doing an official build.
CL based on https://codereview.chromium.org/685123005/ with some additional fixes for the unittests.
BUG=314403
Review URL: https://codereview.chromium.org/695523002
Cr-Commit-Position: refs/heads/master@{#302316}
6 files changed
