FrameSelection::DidChangeFocus doesn't need compositing assert disabler

From code inspection and running the referenced test, there is no
querying of composition state under FrameSelection::UpdateAppearance.
Remove the comment and DisableCompositingQueryAsserts

Bug: 1007989
Change-Id: Ibbd66413bc1cdbe897e474b5fd55d515e8822368
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1856849Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Daniel Libby <dlibby@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#705785}

third_party/blink/renderer/core/editing/frame_selection.cc

@@ -337,9 +337,6 @@ void FrameSelection::NodeWillBeRemoved(Node& node) {
 }
 
 void FrameSelection::DidChangeFocus() {
-  // Hits in
-  // virtual/gpu/compositedscrolling/scrollbars/scrollbar-miss-mousemove-disabled.html
-  DisableCompositingQueryAsserts disabler;
   UpdateAppearance();
 }