Add a utility class to call stream methods implemented with v8 extras.

third_party/WebKit/Source/bindings/core/v8/V8IteratorResultValue.cpp

Index: third_party/WebKit/Source/bindings/core/v8/V8IteratorResultValue.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/V8IteratorResultValue.cpp b/third_party/WebKit/Source/bindings/core/v8/V8IteratorResultValue.cpp
index 739e3a075c546e8039e9ae376604ed72ff869d5f..e2ef6733833451d55b0e292510f2eec26efa1d13 100644
--- a/third_party/WebKit/Source/bindings/core/v8/V8IteratorResultValue.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/V8IteratorResultValue.cpp
@@ -18,4 +18,20 @@ v8::Local<v8::Object> v8IteratorResultValue(v8::Isolate* isolate, bool done, v8:
     return result;
 }
 
+v8::MaybeLocal<v8::Value> v8IteratorUnpack(ScriptState* scriptState, v8::Local<v8::Value> iterator, bool* done)

[haraken, 2015/12/04 01:41:05]

I don't fully understand why this method is needed. If this is only for testing,
can we move this into the test?

[yhirano, 2015/12/04 05:55:47]

I plan to use it in the future, but moving it back to the test file is OK.
Fixed.

+{
+    if (!iterator->IsObject()) {
+        V8ThrowException::throwTypeError(scriptState->isolate(), "The iterator is not an object.");
+        return v8::MaybeLocal<v8::Value>();
+    }
+    v8::Local<v8::Object> object = iterator.As<v8::Object>();
+    v8::Local<v8::Value> doneValue;
+    if (!object->Get(scriptState->context(), v8String(scriptState->isolate(), "done")).ToLocal(&doneValue))
+        return v8::MaybeLocal<v8::Value>();
+    v8::MaybeLocal<v8::Value> r = object->Get(scriptState->context(), v8String(scriptState->isolate(), "value"));
+    if (!r.IsEmpty())
+        *done = doneValue->ToBoolean()->Value();
+    return r;
+}
+
 } // namespace blink