ymalik@ is this something that you can fix?

I also hit this by logging into Facebook and hitting page down a couple times.

It makes it difficult to use debug/dcheck enabled builds on Facebook.

ASSERTION FAILED: isAllowedToQueryCompositingState()
../../third_party/WebKit/Source/core/paint/PaintLayer.cpp(2284) : blink::CompositingState blink::PaintLayer::compositingState() const
1   0x7f61a106b23d blink::ScrollingCoordinator::hasVisibleSlowRepaintViewportConstrainedObjects(blink::FrameView*) const
2   0x7f61a1067ef6 blink::ScrollingCoordinator::mainThreadScrollingReasons() const
3   0x7f61a0ed888f blink::FrameView::shouldScrollOnMainThread() const
4   0x7f61a8a91385 blink::ScrollAnimator::willAnimateToOffset(blink::FloatPoint const&)
5   0x7f61a8a91168 blink::ScrollAnimator::userScroll(blink::ScrollGranularity, blink::FloatSize const&)
6   0x7f61a0f206cd blink::RootFrameViewport::userScroll(blink::ScrollGranularity, blink::FloatSize const&)
7   0x7f61a126bff7 blink::LayoutView::scroll(blink::ScrollGranularity, blink::FloatSize const&)
8   0x7f61a0a42da4 blink::ScrollManager::logicalScroll(blink::ScrollDirection, blink::ScrollGranularity, blink::Node*, blink::Node*)
9   0x7f61a0a42e8e blink::ScrollManager::bubblingScroll(blink::ScrollDirection, blink::ScrollGranularity, blink::Node*, blink::Node*)
10  0x7f61a8721c9c blink::WebViewImpl::scrollViewWithKeyboard(int, int)
11  0x7f61a8720372 blink::WebViewImpl::keyEventDefault(blink::WebKeyboardEvent const&)
12  0x7f61a871ff29 blink::WebViewImpl::handleKeyEvent(blink::WebKeyboardEvent const&)

I can hit this easily by going to this following link and hitting page up/down several times:
http://edition.cnn.com/2016/09/05/politics/philippines-president-rodrigo-duterte-barack-obama/

looking into this..

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2153328998af9d61ff8d7743a2f5bc74f889e7f3

commit 2153328998af9d61ff8d7743a2f5bc74f889e7f3
Author: ymalik <ymalik@chromium.org>
Date: Wed Sep 14 17:07:33 2016

Query compositing state only from UpdateAnimationState

https://codereview.chromium.org/2029323003 attempted to add an optimization
that would run an animation on the MT by querying m_scrollableArea->
shouldScrollOnMainThread. This was wrong because we were querying compositing
state outside of the CompositingClean state.

This reverts that CL.

The original bug was not fixed in the CL that this reverts and that CL was
just wrong.

This CL doesn't have a behavioral change.

BUG= 639100 

Review-Url: https://codereview.chromium.org/2338913002
Cr-Commit-Position: refs/heads/master@{#418596}

[modify] https://crrev.com/2153328998af9d61ff8d7743a2f5bc74f889e7f3/third_party/WebKit/Source/platform/scroll/ScrollAnimator.cpp
[modify] https://crrev.com/2153328998af9d61ff8d7743a2f5bc74f889e7f3/third_party/WebKit/Source/platform/scroll/ScrollAnimatorTest.cpp