Fix error message for Object.observe accept argument

test/mjsunit/es7/object-observe.js

Index: test/mjsunit/es7/object-observe.js
diff --git a/test/mjsunit/es7/object-observe.js b/test/mjsunit/es7/object-observe.js
index 99fa38a8573f1f2db70b3c2a0875d61132202c8b..a6831c09633a41a385e69307dc7e39538c306faf 100644
--- a/test/mjsunit/es7/object-observe.js
+++ b/test/mjsunit/es7/object-observe.js
@@ -1824,3 +1824,16 @@ for (var b1 = 0; b1 < 2; ++b1)
     { object: fun, type: 'add', name: 'name' },
   ]);
 })();
+
+
+(function TestObserveInvalidAcceptMessage() {
+  try {

[arv (Not doing code reviews), 2015/03/12 17:56:25]

Here is another way to write this:

var ex;
try {
  ...
} catch (e) {
  ex = e;
}
assertInstanceof(ex, TypeError);
assertEquals("Object.observe accept must be an array of strings.",
             ex.message);

Then you don't need the return and fail at the end.

+    Object.observe({}, function(){}, "not an object");
+  } catch (e) {
+    assertInstanceof(e, TypeError);
+    assertEquals("Object.observe accept must be an array of strings.",
+                 e.message);

[caitp (gmail), 2015/03/12 18:00:17]

kind of a nit, but the observe_invalid_accept message reads really weirdly to
me. It would be good to make it clear in the message that "accept" is talking
about a parameter name

+    return;
+  }
+  fail("TypeError", "no exception");
+})()