Add [CachedAccessor] attribute to cache (almost) constant accessors (window.document).

third_party/WebKit/Source/bindings/core/v8/V8DOMConfiguration.h

Index: third_party/WebKit/Source/bindings/core/v8/V8DOMConfiguration.h
diff --git a/third_party/WebKit/Source/bindings/core/v8/V8DOMConfiguration.h b/third_party/WebKit/Source/bindings/core/v8/V8DOMConfiguration.h
index 4e6852c0680c142b1184f2a15d5803c3890ceb2c..4dd9670f1540b1c89c69a06eb7d54d09ae5dd6a8 100644
--- a/third_party/WebKit/Source/bindings/core/v8/V8DOMConfiguration.h
+++ b/third_party/WebKit/Source/bindings/core/v8/V8DOMConfiguration.h
@@ -75,8 +75,12 @@ public:
         v8::AccessorNameSetterCallback setter;
         v8::AccessorNameGetterCallback getterForMainWorld;
         v8::AccessorNameSetterCallback setterForMainWorld;
-        // TODO(vogelheim): Figure out how to remove this.
+
+        // TODO(peterssen|vogelheim): Figure out how to remove this.
         FastAccessorBuilderCallback fastGetter;
+        // TODO(peterssen|vogelheim): This has to be removed too since it's only used in accessors.
+        const char* const surrogatePropertyName; // The accessor's 'result' is stored in a private property.
+
         const WrapperTypeInfo* data;
         unsigned settings : 8; // v8::AccessControl
         unsigned attribute : 8; // v8::PropertyAttribute
@@ -102,6 +106,7 @@ public:
         v8::FunctionCallback getterForMainWorld;
         v8::FunctionCallback setterForMainWorld;
         FastAccessorBuilderCallback fastGetter;
+        const char* const surrogatePropertyName; // The accessor is backed by a private property.

[haraken, 2016/09/15 09:26:10]

surrogatePropertyName => keyForCachedAttributeGetter ?

         const WrapperTypeInfo* data;
         unsigned settings : 8; // v8::AccessControl
         unsigned attribute : 8; // v8::PropertyAttribute