[ServiceWorker] Make fetch() method better conformance with the spec.

Source/modules/serviceworkers/FetchHeaderList.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 "FetchHeaderList.h"
 
 #include "core/fetch/CrossOriginAccessControl.h"
 #include "core/xml/XMLHttpRequest.h"
 #include "platform/network/HTTPParsers.h"
@@ skipping 103 matching lines @@
             return true;
     }
     return false;
 }
 
 void FetchHeaderList::clearList()
 {
     m_headerList.clear();
 }
 
+bool FetchHeaderList::containsNonSimpleHeader() const
+{
+    for (size_t i = 0; i < m_headerList.size(); ++i) {
+        if (!isSimpleHeader(m_headerList[i]->first, m_headerList[i]->second))
+            return true;
+    }
+    return false;
+}
+
 bool FetchHeaderList::isValidHeaderName(const String& name)
 {
     // "A name is a case-insensitive byte sequence that matches the field-name
     // token production."
     return isValidHTTPToken(name);
 }
 
 bool FetchHeaderList::isValidHeaderValue(const String& value)
 {
     // "A value is a byte sequence that matches the field-value token production
@@ skipping 37 matching lines @@
 }
 
 bool FetchHeaderList::isForbiddenResponseHeaderName(const String& name)
 {
     // "A forbidden response header name is a header name that is one of:
     // `Set-Cookie`, `Set-Cookie2`"
     return equalIgnoringCase(name, "set-cookie") || equalIgnoringCase(name, "set-cookie2");
 }
 
 } // namespace blink