Remove DisableCompositingQueryAsserts in FV::scrollbarExistenceDidChange

This patch removes a compositing query assert in
FrameView::scrollbarExistenceDidChange because no compositing state is
queried through scrollbarExistenceDidChange.

No new tests.

Review URL: https://codereview.chromium.org/208313016

git-svn-id: svn://svn.chromium.org/blink/trunk@169878 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/frame/FrameView.cpp

@@ -1768,10 +1768,6 @@ void FrameView::scrollbarExistenceDidChange()
     if (!useOverlayScrollbars && needsLayout())
         layout();
 
-    // FIXME: Rather than updating this state synchronously, we should set some dirty bits
-    // and clean them out when updating compositing.
-    // https://code.google.com/p/chromium/issues/detail?id=343756
-    DisableCompositingQueryAsserts disabler;
     if (renderView() && renderView()->usesCompositing()) {
         renderView()->compositor()->frameViewScrollbarsExistenceDidChange();