Add a fuzzer for the feature policy string parser.

third_party/WebKit/Source/platform/feature_policy/FeaturePolicyFuzzer.cpp

 // Copyright 2016 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 "platform/json/JSONParser.h"
+#include "platform/feature_policy/FeaturePolicy.h"
 
-#include "platform/json/JSONValues.h"
+#include "platform/heap/Handle.h"
 #include "platform/testing/BlinkFuzzerTestSupport.h"
+#include "platform/weborigin/SecurityOrigin.h"
+#include "wtf/Vector.h"
 #include "wtf/text/WTFString.h"
+#include <memory>
 #include <stddef.h>
 #include <stdint.h>
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  blink::parseJSON(WTF::String(data, size));
+  WTF::Vector<WTF::String> messages;
+  RefPtr<blink::SecurityOrigin> origin =
+      blink::SecurityOrigin::createFromString("https://example.com/");
+  std::unique_ptr<blink::FeaturePolicy> policy =
+      blink::FeaturePolicy::createFromParentPolicy(nullptr, origin);
+  policy->setHeaderPolicy(WTF::String(data, size), messages);
   return 0;
 }
 
 extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv) {
   blink::InitializeBlinkFuzzTest(argc, argv);
   return 0;
 }