Revert of Update NTP to new material design spec. (patchset #2 id:20001 of https://codereview.chromium.org/1960553003/ )

Reason for revert:
Regression cause in incognito: https://bugs.chromium.org/p/chromium/issues/detail?id=610192

Original issue's description:
> Update NTP to new material design spec.
>
> Also add a feature flag so we can disable if necessary.
>
> Screenshots here of NTP with snippets off and snippets on:
> http://imgur.com/a/Wd04S
>
> BUG=609112
>
> Committed: https://crrev.com/61ca55404d889f1c66821603075ecd096958e5b7
> Cr-Commit-Position: refs/heads/master@{#392250}

TBR=bauerb@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=609112

Review-Url: https://codereview.chromium.org/1962063002
Cr-Commit-Position: refs/heads/master@{#392382}
13 files changed