Add speculative CHECKs to track down a failing ASSERT

third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp

Index: third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp
index cb2ddbe16713106f5bbe855a283726a29aa28536..3e6ffb9657a0c2482338073b276d6f2224119fbc 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp
@@ -1168,6 +1168,10 @@ void LayoutBlockFlow::layoutBlockChildren(bool relayoutChildren, SubtreeLayoutSc
 
     while (next) {
         LayoutBox* child = next;
+        // TODO(foolip): Speculative CHECK to crash if any non-LayoutBox
+        // children ever appear, the childrenInline() check at the call site
+        // should make this impossible. crbug.com/632848
+        CHECK(child->nextSibling()->isBox());
         next = child->nextSiblingBox();
 
         child->setMayNeedPaintInvalidation();