Move performance module/ to oilpan

Source/modules/performance/WorkerPerformance.h

Index: Source/modules/performance/WorkerPerformance.h
diff --git a/Source/modules/performance/WorkerPerformance.h b/Source/modules/performance/WorkerPerformance.h
index 3f450403f7bc395ae3a0c12f8f9f290adb99208c..37d3cada482ba3211377135e57f5c40d77d6e5ab 100644
--- a/Source/modules/performance/WorkerPerformance.h
+++ b/Source/modules/performance/WorkerPerformance.h
@@ -41,13 +41,16 @@ namespace WebCore {
 
 class ExecutionContext;
 
-class WorkerPerformance : public ScriptWrappable, public RefCounted<WorkerPerformance> {
+class WorkerPerformance : public ScriptWrappable, public RefCountedWillBeGarbageCollectedFinalized<WorkerPerformance> {

[haraken, 2014/02/07 05:49:46]

Mads: It's a shame that we have to use GarbageCollected"Finalized" for objects
that inherit from ScriptWrappable, because most DOM objects inherit from
ScriptWrappable.

ScriptWrappable's destructor does nothing in terms of object lifetime, but the
destructor flips a bit of a ScriptWrappable's member for preventing security
exploit. (See
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...)

Do you have any idea to remove ScriptWrappable's destructor?

[haraken, 2014/02/07 05:56:50]

Also I noticed that RefCountedWillBeGarbageCollectedFinalized must be the
left-most class of WorkerPerformance. I'd be happy if Ian's plugin will catch
this kind of error :)

[zerny-chromium, 2014/02/07 05:58:04]

I'll let Mads answer that, but on the branch we actually use GarbageCollected<T>
for a few classes that don't have any destruction code besides that of
ScriptWrappable (eg, NamedNodeMap, WebKitCSSMatrix, etc.).

On another note, I'd swap the order of ScriptWrappable and
RefCountedGarbageCollected. Once it becomes GarbageCollected it should be
left-most.

[tkent, 2014/02/07 06:07:55]

I didn't know this rule.  Do we have a documentation about it?

[Mads Ager (chromium), 2014/02/07 09:28:34]

That is indeed a shame. We should see if we can come up with something that can
provide the same security guarantees but does not require us to run the
destructor. I don't see how to do that simply at this point. Let's keep it in
mind and see if we can come up with idea. 

+    DECLARE_GC_INFO;
 public:
-    static PassRefPtr<WorkerPerformance> create() { return adoptRef(new WorkerPerformance()); }
+    static PassRefPtrWillBeRawPtr<WorkerPerformance> create() { return adoptRefWillBeNoop(new WorkerPerformance()); }
     ~WorkerPerformance();
 
     double now(ExecutionContext*) const;
 
+    void trace(Visitor*) { }
+
 private:
     WorkerPerformance();
 };