Support whitelisting to handle insecure origins as trustworthy origins

The whitelist is given and initialized via
--unsafety-treat-insecure-origin-as-secure command-line flag. This needs to be specified with --user-data-dir
to take effect.

Specifying this flag shows a security banner:
"You are using unsupported command-line flag: ....
Stability and security will suffer."

Depends on blink-side patch:
https://codereview.chromium.org/1082173003/

BUG=441605
TEST=manual (to see SW on http works with command-line flag & the security banner is shown)
TEST=unit_tests:SecureOriginWhiteList.UnsafetyTreatInsecureOriginAsSecure
TEST=content_unittests:URLSchemesTest.IsOriginSecure
TEST=content_unittests:ServiceWorkerDispatcherHostTest.*

Review URL: https://codereview.chromium.org/1072933006

Cr-Commit-Position: refs/heads/master@{#327875}
12 files changed