Fix test after r21299.

test/cctest/test-heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3901 matching lines @@
                    "function foo%d(x) { with (x) { return 1 + x; } };"
                    "bar%d();"
                    "bar%d();"
                    "bar%d();"
                    "%OptimizeFunctionOnNextCall(bar%d);"
                    "bar%d();", i, i, i, i, i, i, i, i);
       CompileRun(source.start());
     }
     heap->CollectAllGarbage(i::Heap::kNoGCFlags);
   }
-  WeakHashTable* table = WeakHashTable::cast(heap->weak_object_to_code_table());
-  CHECK_EQ(0, table->NumberOfElements());
+  int elements = 0;
+  if (heap->weak_object_to_code_table()->IsHashTable()) {
+    WeakHashTable* t = WeakHashTable::cast(heap->weak_object_to_code_table());
+    elements = t->NumberOfElements();
+  }
+  CHECK_EQ(0, elements);
 }
 
 
 static Handle<JSFunction> OptimizeDummyFunction(const char* name) {
   EmbeddedVector<char, 256> source;
   OS::SNPrintF(source,
               "function %s() { return 0; }"
               "%s(); %s();"
               "%%OptimizeFunctionOnNextCall(%s);"
               "%s();", name, name, name, name, name);
@@ skipping 306 matching lines @@
       "array;");
 
   Handle<JSObject> o =
       v8::Utils::OpenHandle(*v8::Handle<v8::Object>::Cast(result));
   CHECK(heap->InOldPointerSpace(o->elements()));
   CHECK(heap->InOldPointerSpace(*o));
   Page* page = Page::FromAddress(o->elements()->address());
   CHECK(page->WasSwept() ||
         Marking::IsBlack(Marking::MarkBitFrom(o->elements())));
 }