Use WeakCell to handle the script wrapper cache

Use WeakCell to handle the script wrapper cache

The script wrapper cache used the API weak handles to provide a weak link from Script to ScriptWrapper. We want to change the way API weakness works, and in this context it's best to get rid of users of the API that don't need to be users.

R=ulan@chromium.org
BUG=

Committed: https://code.google.com/p/v8/source/detail?r=24622

[ulan, 2014-10-14 15:45:56]

lgtm

https://codereview.chromium.org/659513003/diff/1/src/serialize.cc
File src/serialize.cc (right):

https://codereview.chromium.org/659513003/diff/1/src/serialize.cc#newcode2024
src/serialize.cc:2024: HeapObject* clear =
heap_object->GetHeap()->undefined_value();
Since we rebuild the WeakCell list on every GC, serialization should work
correctly.

https://codereview.chromium.org/659513003/diff/1/src/serialize.cc#newcode2025
src/serialize.cc:2025: Script::cast(heap_object)->set_wrapper(clear);
Should we also isolate->counters()->script_wrappers()->Decrement() ?

[Erik Corry Chromium.org, 2014-10-15 09:24:54]

I removed the special handling under serialization, since it should just work
with WeakCell.

[ulan, 2014-10-15 09:56:17]

On 2014/10/15 09:24:54, Erik Corry Chromium.org wrote:
> I removed the special handling under serialization, since it should just work
> with WeakCell.

lgtm

[Erik Corry Chromium.org, 2014-10-15 10:11:20]

Committed patchset #2 (id:20001) manually as 24622 (presubmit successful).