Reland "chromeos: makes resizes smoother with mash"

This reverts commit 643813e151f28b042b469006e265538363547aca.

Reason for revert: My test was wrong, we actually block mouse on device in certain modes. Sorry for the noise.

Original change's description:
> Revert "chromeos: makes resizes smoother with mash"
> 
> This reverts commit b805090b40d7450d3ab7375942af34ed69cd94cb.
> 
> Reason for revert: This makes the mouse get stuck hidden on device.
> 
> Original change's description:
> > chromeos: makes resizes smoother with mash
> > 
> > This contains two changes:
> > 1. Adds call from ClientRoot to Compositor::OnChildResizing(). This ensures
> >    that WindowTreeHost doesn't dispatch move events until the frame has been
> >    activated.
> > 2. Converts resetting of pointer moves lock from OnCompositingDidCommit()
> >    to OnCompositingEnded(). OnCompositingDidCommit() seems to be called much
> >    to earlier in the mash case, and results in jank when resizing.
> > 
> > BUG=929914
> > TEST=none
> > 
> > Change-Id: I68d87d6e7f237f246c2fad6218d9da5356c98641
> > Reviewed-on: https://chromium-review.googlesource.com/c/1467917
> > Commit-Queue: Scott Violet <sky@chromium.org>
> > Reviewed-by: Saman Sami <samans@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#631743}
> 
> TBR=sky@chromium.org,samans@chromium.org
> 
> Change-Id: Iaf103ed66885da652c7013fcc412b0269e10b303
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: 929914
> Reviewed-on: https://chromium-review.googlesource.com/c/1470935
> Reviewed-by: Scott Violet <sky@chromium.org>
> Commit-Queue: Scott Violet <sky@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#631803}

TBR=sky@chromium.org,samans@chromium.org

Change-Id: I828256b878dfb8f5a8ec0bbd6c6c533e091ddb5f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 929914
Reviewed-on: https://chromium-review.googlesource.com/c/1471010
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#631820}
7 files changed