Add forEach() to CSSVariablesMap

LayoutTests/fast/css/variables/cssom-read.html

Index: LayoutTests/fast/css/variables/cssom-read.html
diff --git a/LayoutTests/fast/css/variables/cssom-read.html b/LayoutTests/fast/css/variables/cssom-read.html
index b56cc96229d337e9293a856aa471888596bef49a..115c5aa577ce64c538f827b278387850609453ef 100644
--- a/LayoutTests/fast/css/variables/cssom-read.html
+++ b/LayoutTests/fast/css/variables/cssom-read.html
@@ -9,6 +9,18 @@ if (window.testRunner) {
 
 var pre = document.querySelector("pre");
 
+function outputForEach (styleVar) {
+    var varList = [];
+    styleVar.forEach(function(value, name) { varList.push([name, value]); });
+    for (var i = 0; i < varList.length; i++) {
+        pre.innerText += varList[i][0] + ": " + varList[i][1] + "\n";
+    }
+}
+
+pre.innerText += "Equal variables declaration objects on multiple accesses: ";
+pre.innerText += ((pre.style.var === pre.style.var) ? "pass": "fail") + "\n";
+pre.innerText += "\n";
+
 pre.innerText += "Inline style CSS text: " + pre.style.cssText + "\n";
 pre.innerText += "\n";
 
@@ -20,6 +32,10 @@ pre.innerText += "a: " + pre.style.var.get("a") + "\n";
 pre.innerText += "b: " + pre.style.var.get("b") + "\n";
 pre.innerText += "\n";
 
+pre.innerText += "Enumerate vars:\n";
+outputForEach(pre.style.var);
+pre.innerText += "\n";
+
 pre.innerText += "Access non existent var:\n";
 pre.innerText += "z: " + pre.style.var.get("z") + "\n";
 pre.innerText += "\n";
@@ -37,5 +53,9 @@ pre.innerText += "a: " + pre.style.var.get("a") + "\n";
 pre.innerText += "b: " + pre.style.var.get("b") + "\n";
 pre.innerText += "c: " + pre.style.var.get("c") + "\n";
 pre.innerText += "d: " + pre.style.var.get("d") + "\n";
+pre.innerText += "\n";
+
+pre.innerText += "Enumerate vars:\n";
+outputForEach(pre.style.var);
 
 </script>