Revert "MacViews: Re-enable single ui::Compositor view"

This reverts commit 6f4d713f35161bc425b1032956e2b12fdd5f639f.

Reason for revert: This seems to have caused https://crbug.com/846691

Original change's description:
> MacViews: Re-enable single ui::Compositor view
> 
> Decide at initialization whether or not a RenderWidgetHostViewMac will
> be displayed in its NSView or through a ui::Compositor.
> 
> This fixes a bug whereby some windows (DevTools is a good example)
> would, through the vagaries of initialization order, draw a single
> frame to the NSView, which would then never go away, and cover up the
> ui::Compositor's version of the content (which was then updating
> correctly, though not visible).
> 
> Bug: 840173, 845807
> Change-Id: If051d249956b10c9e56450ed1f58b9048d331562
> Reviewed-on: https://chromium-review.googlesource.com/1070764
> Commit-Queue: ccameron <ccameron@chromium.org>
> Reviewed-by: Sidney San Martín <sdy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#561717}

TBR=ccameron@chromium.org,sdy@chromium.org

Change-Id: Ic25ee96c567c3531d91ec5431f10d15d34bfee82
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 840173, 845807
Reviewed-on: https://chromium-review.googlesource.com/1073089
Reviewed-by: Fady Samuel <fsamuel@chromium.org>
Commit-Queue: Fady Samuel <fsamuel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561850}
2 files changed