simplify GlobalValueMap calls to DisposeWeak

test/cctest/test-api.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 3335 matching lines @@
   static K KeyFromWeakCallbackInfo(
       const v8::WeakCallbackInfo<WeakCallbackDataType>& data) {
     return data.GetParameter()->key;
   }
   static void DisposeCallbackData(WeakCallbackDataType* data) { delete data; }
   static void Dispose(v8::Isolate* isolate, v8::Global<V> value, K key) {
     CHECK_EQ(IntKeyToVoidPointer(key),
              v8::Object::GetAlignedPointerFromInternalField(value, 0));
   }
   static void DisposeWeak(
-      v8::Isolate* isolate,
-      const v8::WeakCallbackInfo<WeakCallbackDataType>& info, K key) {
+      const v8::WeakCallbackInfo<WeakCallbackDataType>& info) {
+    K key = KeyFromWeakCallbackInfo(info);
     CHECK_EQ(IntKeyToVoidPointer(key), info.GetInternalField(0));
     DisposeCallbackData(info.GetParameter());
   }
 };
 
 }  // namespace
 
 
 TEST(GlobalValueMap) {
   typedef v8::GlobalValueMap<int, v8::Object,
@@ skipping 18525 matching lines @@
   }
   {
     v8::TryCatch try_catch;
     uint16_t* data = reinterpret_cast<uint16_t*>(buffer);
     CHECK(v8::String::NewFromTwoByte(isolate, data, v8::String::kNormalString,
                                      length).IsEmpty());
     CHECK(!try_catch.HasCaught());
   }
   free(buffer);
 }