IDL: Add build target for IDL dictionary impl generation in core

Source/core/testing/DictionaryTest.cpp

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "DictionaryTest.h"
+
+#include "core/testing/TestingDictionary.h"
+
+namespace blink {
+
+DictionaryTest::DictionaryTest()
+{
+    ScriptWrappable::init(this);
+}
+
+DictionaryTest::~DictionaryTest()
+{
+}
+
+void DictionaryTest::set(const TestingDictionary* testingDictionary)
+{
+    if (testingDictionary->hasLongMember())
+        m_longMember = testingDictionary->longMember();
+    m_stringMember = testingDictionary->stringMember();

[haraken, 2014/08/26 04:00:40]

Just help me understand: Are you assuming that Dictionary users selectively use
the hasXXX() checks depending on whether the member is nullable or not? Or are
you assuming that Dictionary users (can) always use the hasXXX() checks?

Specifically, I wonder if we should or should not or can add the
testingDictionary->hasStringMember() check here.

[bashi, 2014/08/27 05:06:32]

It depends on whether a member has a default value, rather than is nullable. We
can always use hasXXX() method, but when a member has a default value which is
not null, hasXXX() always returns true. That's why I omit hasStringMember()
check. We need to check hasXXX() when the member is primitive type and nullable,
because Nullable<double>::get() doesn't make sense when the value is null.

+    if (testingDictionary->hasBooleanOrNullMember())
+        m_booleanOrNullMember = testingDictionary->booleanOrNullMember();
+    if (testingDictionary->hasStringSequenceMember())
+        m_stringSequenceMember = testingDictionary->stringSequenceMember();
+}
+
+TestingDictionary* DictionaryTest::get()
+{
+    TestingDictionary* result = TestingDictionary::create();
+    if (m_longMember)
+        result->setLongMember(m_longMember.get());
+    result->setStringMember(m_stringMember);
+    if (m_booleanOrNullMember)
+        result->setBooleanOrNullMember(m_booleanOrNullMember);
+    result->setStringSequenceMember(m_stringSequenceMember);

[haraken, 2014/08/26 04:00:40]

Ditto. It's not clear to me when the Dictionary users need the if checks. I'd
like to understand the rule.

[bashi, 2014/08/27 05:06:32]

It depends on how the dictionary is defined and the user of dictionary should
know which member has default value. For example, FontFaceDescriptors dictionary
is used by FontFace, and the author of FontFace should know how
FontFaceDescriptors is defined.

+    return result;
+}
+
+void DictionaryTest::trace(Visitor* visitor)

[haraken, 2014/08/26 04:00:40]

Drop |visitor|.

[bashi, 2014/08/27 05:06:32]

Done.

+{
+}
+
+}