Reapply 169371 "DevTools: defer styles delta calculation to until the end of the task"

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index db5f3b0b2f44c73ef3afdf7fcdcee96e46f19ae8..456a185280722641c9fec85a2160c1cdc5522d64 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -2057,6 +2057,7 @@ void Document::detach(const AttachContext& context)
 
     if (page())
         page()->documentDetached(this);
+    InspectorInstrumentation::documentDetached(this);
 
     if (m_frame->loader().client()->sharedWorkerRepositoryClient())
         m_frame->loader().client()->sharedWorkerRepositoryClient()->documentDetached(this);