[Blink/SPv175] Disable snapping DCHECK in CompositingLayerPropertyUpdater

This DCHECK has been hit by developers too often, making a checked build
useless. Disabling the DCHECK in the meantime while a fix can be done.

BUG=816490

Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Change-Id: I3b9d020978b4ebabf00233c35ba3059a8ba2f9fd
Reviewed-on: https://chromium-review.googlesource.com/998529
Commit-Queue: Tien-Ren Chen <trchen@chromium.org>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548545}

third_party/WebKit/Source/core/paint/compositing/CompositingLayerPropertyUpdater.cpp

@@ -31,7 +31,8 @@ void CompositingLayerPropertyUpdater::Update(const LayoutObject& object) {
   LayoutPoint layout_snapped_paint_offset =
       fragment_data.PaintOffset() - mapping->SubpixelAccumulation();
   IntPoint snapped_paint_offset = RoundedIntPoint(layout_snapped_paint_offset);
-  DCHECK(layout_snapped_paint_offset == snapped_paint_offset);
+  // TODO(crbug.com/816490): Re-enable this check once it is fixed.
+  // DCHECK(layout_snapped_paint_offset == snapped_paint_offset);
 
   Optional<PropertyTreeState> container_layer_state;
   auto SetContainerLayerState =