GitLab

Applying new styling, with some refactoring and bug fixes. Details:

- Sizing and positioning tweaks.
- Change of assets for "X" and for default favicon (if it's missing).
  - Using image as mask, and setting color by CSS (since design uses
    solid colors).
- The new PNG files have been minimized.
- Fixed bug: "Undo" and "Restore All" links continue to be selectable
  via tab after they fades out.
- Alternative Google logo (white): using image as mask and setting
  background color to #eee.  Will delete old image for M39.
- Theme title color in title.html <iframe>: now injecting it from local
  NTP in "c=RRGGBBAA" format. The old behavior of reading it from
  <iframe> and using it to override "c=RRGGBB" are kept, for
  compatibility with server-side NTP.

BUG=407943
NOTRY=1
R=mathp@chromium.org, oshima@chromium.org

Review URL: https://codereview.chromium.org/512583002

Cr-Commit-Position: refs/heads/master@{#292820}