V8ScriptValueSerializer: Add a separate version 'envelope' for Blink format version.

third_party/WebKit/LayoutTests/crypto/subtle/resources/common.js

 function logError(error)
 {
     debug("error is: " + error.toString());
 }
 
 // Verifies that the given "bytes" holds the same value as "expectedHexString".
 // "bytes" can be anything recognized by "bytesToHexString()".
 function bytesShouldMatchHexString(testDescription, expectedHexString, bytes)
 {
     expectedHexString = "[" + expectedHexString.toLowerCase() + "]";
@@ skipping 95 matching lines @@
         self.channel.port2.postMessage(key);
     });
 }
 
 // Logging the serialized format ensures that if it changes it will break tests.
 function logSerializedKey(o)
 {
     if (internals) {
         // Removing the version tag from the output so serialization format changes don't need to update all the crypto tests.
         var serialized = internals.serializeObject(o);
-        var serializedWithoutVersion = new Uint8Array(serialized, 2);
+        var serializedWithoutVersion = new Uint8Array(serialized, 4);
         debug("Serialized key bytes: " + bytesToHexString(serializedWithoutVersion));
     }
 }
 
 function shouldEvaluateAs(actual, expectedValue)
 {
     if (typeof expectedValue == "string")
         return shouldBeEqualToString(actual, expectedValue);
     return shouldEvaluateTo(actual, expectedValue);
 }
@@ skipping 30 matching lines @@
       // Expected to succeed.
       debug("SUCCESS");
       return result;
     }, function(error) {
       debug("FAILED: " + error.toString());
 
       // Re-throw the error.
       throw new Error("Test FAILED: " + message);
     });
 }