If a page calls |window.focus()|, kick it out of fullscreen.

BUG=776418, 800056

Change-Id: I1880fe600e4814c073f247c43b1c1ac80c8fc017
Reviewed-on: https://chromium-review.googlesource.com/852378
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Reviewed-by: Philip Jägenstedt <foolip@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533790}
InputDeviceCapabilitiesConstants* DOMWindow::GetInputDeviceCapabilities() {
  if (!input_capabilities_)
    input_capabilities_ = new InputDeviceCapabilitiesConstants;
  return input_capabilities_;
}

InputDeviceCapabilitiesConstants* DOMWindow::GetInputDeviceCapabilities() {
  if (!input_capabilities_)
    input_capabilities_ = new InputDeviceCapabilitiesConstants;
  return input_capabilities_;
}
