Implement platform deleters per spec.

Source/core/storage/Storage.cpp

Index: Source/core/storage/Storage.cpp
diff --git a/Source/core/storage/Storage.cpp b/Source/core/storage/Storage.cpp
index 76abd82a300ffeb590d682add181d3dc831bcee6..a1481009ff070cac7cab2bba96f7e19e002216e8 100644
--- a/Source/core/storage/Storage.cpp
+++ b/Source/core/storage/Storage.cpp
@@ -78,20 +78,24 @@ bool Storage::anonymousIndexedSetter(unsigned index, const AtomicString& value,
     return anonymousNamedSetter(AtomicString::number(index), value, exceptionState);
 }
 
-bool Storage::anonymousNamedDeleter(const AtomicString& name, ExceptionState& exceptionState)
+bool Storage::anonymousNamedDeleter(const AtomicString& name, bool& result, ExceptionState& exceptionState)

[haraken, 2013/12/17 15:59:20]

I'm a bit confused. What's the difference between the |result| parameter and the
returned value? Do we need both?

[sof, 2013/12/17 16:20:08]

We need to represent three outcomes,

 * property deleted ok.
 * property not deleted (non-configurable or other platform object
restrictions.)
 * property not known (4.7.4.2 does not apply; 4.7.4.3 should happen instead.)

[sof, 2013/12/17 16:24:38]

Forgot to say/ask...if the preference is to encode this via an enum instead,
then we can definitely switch.

[haraken, 2013/12/17 16:51:05]

Thanks for the clarification! enum sounds better to me.

 {
+    result = false;
     bool found = contains(name, exceptionState);
     if (!found || exceptionState.hadException())
         return false;
     removeItem(name, exceptionState);
     if (exceptionState.hadException())
-        return false;
+        return true;
+    result = true;
     return true;
 }
 
 bool Storage::anonymousIndexedDeleter(unsigned index, ExceptionState& exceptionState)
 {
-    return anonymousNamedDeleter(AtomicString::number(index), exceptionState);
+    bool result;
+    anonymousNamedDeleter(AtomicString::number(index), result, exceptionState);
+    return true;
 }
 
 void Storage::namedPropertyEnumerator(Vector<String>& names, ExceptionState& exceptionState)