Structured cloning: improve DataCloneError reporting.

LayoutTests/fast/canvas/webgl/script-tests/arraybuffer-transfer-of-control.js

Index: LayoutTests/fast/canvas/webgl/script-tests/arraybuffer-transfer-of-control.js
diff --git a/LayoutTests/fast/canvas/webgl/script-tests/arraybuffer-transfer-of-control.js b/LayoutTests/fast/canvas/webgl/script-tests/arraybuffer-transfer-of-control.js
index a239803dbaef0008d44f1fb192faa02fc13eb44c..a2f3a1efd1772dde80be72461f0b3256ebfdddb8 100644
--- a/LayoutTests/fast/canvas/webgl/script-tests/arraybuffer-transfer-of-control.js
+++ b/LayoutTests/fast/canvas/webgl/script-tests/arraybuffer-transfer-of-control.js
@@ -31,7 +31,7 @@ var allBufferTypes =
     ["Uint16", Uint16Array, 2],
     ["Float32", Float32Array, 4],
     ["Float64", Float64Array, 8],
-    ["DataView", DataView, 1] 
+    ["DataView", DataView, 1]
 ];
 
 function isTypedArray(view)
@@ -55,6 +55,11 @@ function isArrayBuffer(buffer)
     return (buffer instanceof ArrayBuffer);
 }
 
+function isDataCloneError(e)
+{
+    return (e.name === "DataCloneError");
+}
+
 function assertBufferClosed(testName, buffer)
 {
     if (buffer === null) {
@@ -257,6 +262,10 @@ function wrapFailSend(testName, message, xfer)
     try {
         window.postMessage(message, '*', xfer);
     } catch (e) {
+        if (!isDataCloneError(e)) {
+            testFailed(testName + ": expected postMessage to throw DataCloneError but it didn't.");
+            return false;
+        }
         return true;
     }
     testFailed(testName + ": expected postMessage to fail but it didn't.");