If JavaScript shows a dialog, cause the page to lose fullscreen.

BUG=670135, 550017, 726761, 728276

Review-Url: https://codereview.chromium.org/2906133004
Cr-Commit-Position: refs/heads/master@{#478884}
void WebContentsImpl::Delete() {
  RenderFrameHost* focused_frame = GetFocusedFrame();
  if (!focused_frame)
    return;

  focused_frame->GetFrameInputHandler()->Delete();
  RecordAction(base::UserMetricsAction("DeleteSelection"));
}

void WebContentsImpl::Delete() {
  RenderFrameHost* focused_frame = GetFocusedFrame();
  if (!focused_frame)
    return;

  focused_frame->GetFrameInputHandler()->Delete();
  RecordAction(base::UserMetricsAction("DeleteSelection"));
}
