Check that RWHI isn't deleted manually while owned by a scoped_ptr in RVHI

BUG=590284

Review URL: https://codereview.chromium.org/1747183002

Cr-Commit-Position: refs/heads/master@{#378844}
void RenderWidgetHostImpl::SetEditCommandsForNextKeyEvent(
    const std::vector<EditCommand>& commands) {
  Send(new InputMsg_SetEditCommandsForNextKeyEvent(GetRoutingID(), commands));
}

void RenderWidgetHostImpl::SetEditCommandsForNextKeyEvent(
    const std::vector<EditCommand>& commands) {
  Send(new InputMsg_SetEditCommandsForNextKeyEvent(GetRoutingID(), commands));
}
