Clean compositing inputs for location APIs for sticky-affected elements.

third_party/WebKit/Source/core/html/HTMLElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLElement.cpp b/third_party/WebKit/Source/core/html/HTMLElement.cpp
index d0d4c083394be934a738e88061b72771157aac13..fc5e646207696f558a4bedba35283483ae116c4e 100644
--- a/third_party/WebKit/Source/core/html/HTMLElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLElement.cpp
@@ -1141,6 +1141,7 @@ const AtomicString& HTMLElement::EventParameterName() {
 }
 
 int HTMLElement::offsetLeftForBinding() {
+  EnsureLifecycleValidForLocationAPIs();

[fs, 2017/04/29 09:59:06]

I think you need this in offsetWidth/Height too (because of the pixelsnapping.)

[smcgruer, 2017/05/01 20:15:15]

Again done, again I'm not sure how to best test this :)

   Element* offset_parent = unclosedOffsetParent();
   if (LayoutBoxModelObject* layout_object = GetLayoutBoxModelObject())
     return AdjustLayoutUnitForAbsoluteZoom(
@@ -1151,6 +1152,7 @@ int HTMLElement::offsetLeftForBinding() {
 }
 
 int HTMLElement::offsetTopForBinding() {
+  EnsureLifecycleValidForLocationAPIs();
   Element* offset_parent = unclosedOffsetParent();
   if (LayoutBoxModelObject* layout_object = GetLayoutBoxModelObject())
     return AdjustLayoutUnitForAbsoluteZoom(