Revert of Enable GPU Rasterization for content with any author defined viewport. (patchset #2 id:20001 of https://codereview.chromium.org/1817583003/ )

Reason for revert:
Reverting until we can debug memory health regressions on WebView.

BUG=596881

Original issue's description:
> Enable GPU Rasterization for content with any author defined viewport.
>
> BUG=591179
>
> Committed: https://crrev.com/b338ee0b3125007b94854e44ed7b6df820c72a75
> Cr-Commit-Position: refs/heads/master@{#382394}

TBR=aelias@chromium.org,pdr@chromium.org,chrishtr@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=591179

Review URL: https://codereview.chromium.org/1868563003

Cr-Commit-Position: refs/heads/master@{#385547}
4 files changed