Implement Blink-in-JS for DOM attributes

Source/core/testing/Internals.js

Index: Source/core/testing/Internals.js
diff --git a/Source/core/testing/Internals.js b/Source/core/testing/Internals.js
index a30335c74888ed9367e021155b1246dc56ad6e07..7e53aa188ea5dabafd57556b96660dd495de56df 100644
--- a/Source/core/testing/Internals.js
+++ b/Source/core/testing/Internals.js
@@ -7,6 +7,12 @@
 installClass("Internals", function(global) {
     var InternalsPrototype = Object.create(Element.prototype);
 
+    InternalsPrototype.constructor = function() {
+        this.m_shortAttribute = -1;
+        this.m_stringAttribute = "xxx";
+        this.m_nodeAttribute = null;
+    }
+
     InternalsPrototype.doNothing = function() {
     }
 
@@ -85,5 +91,24 @@ installClass("Internals", function(global) {
         node.dispatchEvent(event);
     }
 
+    Object.defineProperty(InternalsPrototype, "readonlyShortAttribute", {
+        get: function() { return 123; }
+    });
+
+    Object.defineProperty(InternalsPrototype, "shortAttribute", {
+        get: function() { return this.m_shortAttribute; },
+        set: function(value) { this.m_shortAttribute = value; }
+    });
+
+    Object.defineProperty(InternalsPrototype, "stringAttribute", {
+        get: function() { return this.m_stringAttribute; },
+        set: function(value) { this.m_stringAttribute = value; }
+    });
+
+    Object.defineProperty(InternalsPrototype, "nodeAttribute", {
+        get: function() { return this.m_nodeAttribute; },
+        set: function(value) { this.m_nodeAttribute = value; }
+    });
+
     return InternalsPrototype;
 });