Iterate the UI light theme

[petemill]

Fix brave/brave-browser#961

Hardcoded colors for now, will follow-up with variables for the palette and re-using from Omnibox to ThemeProperties when we validate these values with the designers in the build.

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed.
• Add appropriate QA labels (QA/Needed or QA/No-QA-Needed) to include the closed issue in milestone

Test Plan:

Reviewer Checklist:

• New files have MPL-2.0 license header.
• Request a security/privacy review as needed.
• Adequate test coverage exists to prevent regressions
• Verify test plan is specified in PR before merging to source

[simonhong]

LGTM.

Q: deleting all of our location bar border color is intentional?

[petemill]

@simonhong looks to me like the refresh UI doesn't use the LocationBar border property from ThemeProperties, since the border is set to 0. The only situation there is a border is for the focus ring, which is controlled by #476.

Thanks for the speedy review!

[petemill]

0.55.x 91aa0cc