Revert "Fix page scale limits override"

This reverts commit c1eae0fa80520ccc58c01c722db6e2c2ba929c82.

Reason for revert: Decided on different UX in b/135915002

Original change's description:
> Fix page scale limits override
> 
> In https://crrev.com/53f9afcdecf35a8, we changed the Force Enable Zoom
> setting to also force reset the initial scale factor so that pages that
> specify an initial-scale in the viewport meta tag load fully zoomed out.
> 
> Unfortunately, this caused the bug in 960518 since we always reset the
> initial scale factor to -1 when calling SetIgnoreViewportTagLimits. On
> AndroidTV devices the initial scale is overridden using
> SetInitialPageScaleOverride. This override would be clobbered when
> SetIgnoreViewportTagLimits was called (with false, to ensure the
> override is off).
> 
> This CL fixes the issue by storing the user agent constraints when we
> override them, and resetting them to the original values when turning
> off the override.
> 
> Bug: 960518,929709
> Change-Id: I9d7236ec0991025067504c867fe0d06c9d12c455
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1631710
> Commit-Queue: David Bokan <bokan@chromium.org>
> Auto-Submit: David Bokan <bokan@chromium.org>
> Reviewed-by: Ted Choc <tedchoc@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#663939}

TBR=bokan@chromium.org,tedchoc@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 960518, 929709
Change-Id: I492fa5e1d7fd6e47a8eb6a292b178e86cebb8e88
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1680435
Reviewed-by: David Bokan <bokan@chromium.org>
Commit-Queue: David Bokan <bokan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#673214}
3 files changed