Revert 252889 "Revert 252883 "Remove tests and code for showModa..."

Revert 252889 "Revert 252883 "Remove tests and code for showModa..."

Layout test failures are expected and suppressed on the blink side.

> Revert 252883 "Remove tests and code for showModalDialog"
> 
> This CL broke show-modal-dialog tests in Blink.
> http://test-results.appspot.com/dashboards/flakiness_dashboard.html#group=%40ToT%20Blink&tests=fast/dom/Window/open-window-min-size.html,fast/events/scroll-event-during-modal-dialog.html,fast/events/show-modal-dialog-onblur-onfocus.html,fast/harness/show-modal-dialog.html
> 
> > Remove tests and code for showModalDialog
> > 
> > This deletes the chromium-side implementation logic and a few tests for
> > showModalDialog. I believe more simplification is possible to do without the
> > design constraints imposed by showModalDialog but we should probably start
> > small in case we run into unexpected compat issues.
> > 
> > R=darin
> > BUG=345831
> > 
> > Review URL: https://codereview.chromium.org/165793003
> 
> TBR=jamesr@chromium.org
> 
> Review URL: https://codereview.chromium.org/177263002

TBR=haraken@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=252989

[jamesr, 2014-02-24 21:47:29]

Committed patchset #1 manually as r252989.