Disable compositing query asserts in FrameView::setTransparent.

Followup to r167636.

BUG=none
TBR=ojan@chromium.org

Review URL: https://codereview.chromium.org/176543002

git-svn-id: svn://svn.chromium.org/blink/trunk@167645 bbb929c8-8fbe-4397-9dbb-9b2b20218538