Chrome Version : 51.0.2663.0 (Official Build) 5c3e3aa16e4d6f592742fff247fe2d591c170fd6-refs/heads/master@{#378159}
OS:All,Win 7(Aero enabled)

Precondition: Enable the 'Media Router' flag from chrome://flags.

What steps will reproduce the problem?
1.Launch chrome,navigate to any webpage,click on wrench menu and click on 'cast' option.
2.Once the overlay appears click on omnibox and enter 'test' observe.

Actual:
1.Able to input data in omnibox even if cast overlay is present.
2.Overlapping of cast overlay and suggestion list is seen.

Expected: Should not allow to input data in omnibox if cast overlay is present.

This is a non regression issue,seen from 'M-46'series.