Propagate inert state to OOPIFs when a modal dialog is active

third_party/WebKit/Source/core/dom/Document.cpp

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index fd004e14e8006d5d63120891b1b50603ab0f0694..fb2a20713bb8e7531b83dcbe851a49dd92462f55 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -2184,6 +2184,7 @@ void Document::UpdateStyle() {
   DCHECK(InStyleRecalc());
   DCHECK_EQ(GetStyleResolver(), &resolver);
   lifecycle_.AdvanceTo(DocumentLifecycle::kStyleClean);
+
   if (should_record_stats) {
     TRACE_EVENT_END2(
         "blink,blink_style", "Document::updateStyle", "resolverAccessCount",
@@ -2260,11 +2261,15 @@ void Document::UpdateStyleAndLayout() {
     return;
   }
 
-  if (HTMLFrameOwnerElement* owner = LocalOwner())
+  HTMLFrameOwnerElement* owner = LocalOwner();
+  if (owner)
     owner->GetDocument().UpdateStyleAndLayout();
 
   UpdateStyleAndLayoutTree();
 
+  if (owner)
+    GetFrame()->SetIsInert(owner->IsInert());

[tkent, 2017/06/08 23:53:48]

This was added to fix "!node.NeedsDistributionRecalc()" dcheck failures, right?
I'm not sure if this is a right fix.
hayato@, do you have any advice?

[kenrb, 2017/06/09 15:15:48]

Correct, and I'm not sure it is the right fix either. My earlier attempts were
to update the cached inert values on the Frames whenever an inert attribute
changed, or else when a Frame was attached to its parent element. There were
DCHECKs hit because I was breaking assumptions about elements being style clean.
Re-checking a Frame's inertness during style update, which I added here, seems
to work, but I would welcome better suggestions on how to do it.

[hayato, 2017/06/13 09:48:00]

Using UpdateStyleAndLayout() as a hook for SetIsInert() doesn't look good to me.
What we have to do is calling UpdateDistribution() somewhere so that it doesn't
hit DCHCEK() before calling SetIsInert(), I think.

+
   if (!IsActive())
     return;