color: Use base::Feature to control color correct rendering

Add an explicit enable command line flag in
ShellMainDelegate::BasicStartupComplete to enable this feature
for layout tests, because it is already enabled for layout tests.

R=asvitkine
TBR=avi (content/), xiyuan (chrome/browser/chromeos/login)
BUG=713889

Review-Url: https://codereview.chromium.org/2945453002
Cr-Commit-Position: refs/heads/master@{#480262}
15 files changed