Transform parents of modal windows with modal window. Hide non overview windows.
BUG=304289
TEST=WindowSelectorTest.NonActivatableWindowsHidden,
WindowSelectorTest.ModalChild,
WindowSelectorTest.ClickModalWindowParent
TEST=Open a browser, press Ctrl+O to open a modal window. Enter overview.
Browser should be transformed with modal file open window. Clicking on browser
should activate file open window.
Review URL: https://codereview.chromium.org/
26487003
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227555 0039d316-1c4b-4281-b951-d872f2087c98