IDL: make optional arguments (without default) explicit sometimes

Source/modules/serviceworkers/Headers.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 "modules/serviceworkers/Headers.h"
 
 #include "bindings/core/v8/Dictionary.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/fetch/FetchUtils.h"
@@ skipping 192 matching lines @@
     if (m_guard == RequestNoCORSGuard && !FetchUtils::isSimpleHeader(AtomicString(name), AtomicString(value)))
         return;
     // "5. Otherwise, if guard is |response| and |name| is a forbidden response
     //     header name, return."
     if (m_guard == ResponseGuard && FetchUtils::isForbiddenResponseHeaderName(name))
         return;
     // "6. Set |name|/|value| in header list."
     m_headerList->set(name, value);
 }
 
-void Headers::forEach(PassOwnPtr<HeadersForEachCallback> callback, ScriptValue& thisArg)
+void Headers::forEach(PassOwnPtr<HeadersForEachCallback> callback, const Optional<ScriptValue>& thisArg)
 {
-    forEachInternal(callback, &thisArg);
-}
-
-void Headers::forEach(PassOwnPtr<HeadersForEachCallback> callback)
-{
-    forEachInternal(callback, 0);
+    TrackExceptionState exceptionState;
+    for (size_t i = 0; i < m_headerList->size(); ++i) {
+        if (thisArg.isMissing())
+            callback->handleItem(m_headerList->list()[i]->second, m_headerList->list()[i]->first, this);
+        else
+            callback->handleItem(thisArg.get(), m_headerList->list()[i]->second, m_headerList->list()[i]->first, this);
+        if (exceptionState.hadException())
+            break;
+    }
 }
 
 void Headers::fillWith(const Headers* object, ExceptionState& exceptionState)
 {
     ASSERT(m_headerList->size() == 0);
     // "To fill a Headers object (|this|) with a given object (|object|), run
     // these steps:"
     // "1. If |object| is a Headers object, copy its header list as
     //     |headerListCopy| and then for each |header| in |headerListCopy|,
     //     retaining order, append header's |name|/|header|'s value to
@@ skipping 71 matching lines @@
     ScriptWrappable::init(this);
 }
 
 Headers::Headers(FetchHeaderList* headerList)
     : m_headerList(headerList)
     , m_guard(NoneGuard)
 {
     ScriptWrappable::init(this);
 }
 
-void Headers::forEachInternal(PassOwnPtr<HeadersForEachCallback> callback, ScriptValue* thisArg)
-{
-    TrackExceptionState exceptionState;
-    for (size_t i = 0; i < m_headerList->size(); ++i) {
-        if (thisArg)
-            callback->handleItem(*thisArg, m_headerList->list()[i]->second, m_headerList->list()[i]->first, this);
-        else
-            callback->handleItem(m_headerList->list()[i]->second, m_headerList->list()[i]->first, this);
-        if (exceptionState.hadException())
-            break;
-    }
-}
-
 void Headers::trace(Visitor* visitor)
 {
     visitor->trace(m_headerList);
 }
 
 } // namespace blink