Enable ASSERT in positionFromPaintInvalidationContainer

We are doing paint invalidations after compositing updates
so nothing blocks enabling it anymore.

BUG=360286

Review URL: https://codereview.chromium.org/479563006

git-svn-id: svn://svn.chromium.org/blink/trunk@180474 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/rendering/RenderObject.cpp

@@ -1342,8 +1342,7 @@ void RenderObject::addChildFocusRingRects(Vector<IntRect>& rects, const LayoutPo
 
 LayoutPoint RenderObject::positionFromPaintInvalidationContainer(const RenderLayerModelObject* paintInvalidationContainer, const PaintInvalidationState* paintInvalidationState) const
 {
-    // FIXME: This assert should be re-enabled when we move paint invalidation to after compositing update. crbug.com/360286
-    // ASSERT(containerForPaintInvalidation() == paintInvalidationContainer);
+    ASSERT(containerForPaintInvalidation() == paintInvalidationContainer);
 
     if (paintInvalidationContainer == this)
         return LayoutPoint();