Revert of Revert of Snap RWHVA and resize the legacy window on Windows whenever the ancestor window's bounds change.

Revert of Revert of Snap RWHVA and resize the legacy window on Windows whenever the ancestor window's bounds change. (patchset #1 id:1 of https://codereview.chromium.org/1063083003/)

Reason for revert:
Reverting this didn't help, relanding.

Original issue's description:
> Revert of Snap RWHVA and resize the legacy window on Windows whenever the ancestor window's bounds change. (patchset #12 id:220001 of https://codereview.chromium.org/1062273002/)
>
> Reason for revert:
> Speculative, possibly caused lots of browsert_tests redness on a bot that runs browser_tests with an official build (and a different compiler, but all the redness we fixed on official builds so far were caused by the builds being official, not because of the compiler): http://build.chromium.org/p/chromium.fyi/builders/CrWinClang%20tester/builds/285 (see http://crbug.com/467929)
>
> Original issue's description:
> > Snap RWHVA and resize the legacy window on Windows whenever the ancestor window's bounds change.
> >
> > The bookmark bar is hidden through the fast resize code path where in the Renderer is informed about
> > the actual size minus the bookmar bar before the bookmark bar is hidden. To ensure that the RWHVA is snapped
> > to pixel boundaries and the legacy window is resized we observe bounds changed events on the parent of the WCVA
> > window which is the NativeViewHost clipping window. Reason for doing this is the layer for the window hosted by WCVA
> > verifies if the stored bounds is the same as the one coming in and ignores the change if yes.
> >
> > For more context and a general discussion of the reason why this bug happens please visit this link
> > https://codereview.chromium.org/1009533005/
> >
> > BUG=469857, 468669
> >
> > Committed: https://crrev.com/e6a9b7fff4802ac6796250987be4d52204716392
> > Cr-Commit-Position: refs/heads/master@{#324743}
>
> TBR=sky@chromium.org,scottmg@chromium.org,cpu@chromium.org,ananta@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=469857, 468669
>
> Committed: https://crrev.com/67bcbf34229acff21e300e630ee871b0a64871b4
> Cr-Commit-Position: refs/heads/master@{#324804}

TBR=sky@chromium.org,scottmg@chromium.org,cpu@chromium.org,ananta@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=469857, 468669
Committed: https://crrev.com/144ff57dc021b068d0df1100406c59c25f724b99
Cr-Commit-Position: refs/heads/master@{#324808}

[Nico, 2015-04-13 02:58:32]

Created Revert of Revert of Snap RWHVA and resize the legacy window on Windows
whenever the ancestor window's bounds change.