Simplify OriginTrialContext and the way it validates tokens.

content/renderer/origin_trials/web_trial_token_validator_impl.cc

 // 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 "content/renderer/origin_trials/web_trial_token_validator_impl.h"
 
 #include "content/common/origin_trials/trial_token_validator.h"
+#include "third_party/WebKit/public/platform/WebOriginTrialTokenStatus.h"
 
 namespace content {
 
 WebTrialTokenValidatorImpl::WebTrialTokenValidatorImpl() {}
 WebTrialTokenValidatorImpl::~WebTrialTokenValidatorImpl() {}
 
 blink::WebOriginTrialTokenStatus WebTrialTokenValidatorImpl::validateToken(
     const blink::WebString& token,
     const blink::WebSecurityOrigin& origin,
-    const blink::WebString& featureName) {
-  return TrialTokenValidator::ValidateToken(token.utf8(), origin,
-                                            featureName.utf8());
+    blink::WebString* feature_name) {
+  std::string feature;
+  blink::WebOriginTrialTokenStatus status =
+      TrialTokenValidator::ValidateToken(token.utf8(), origin, &feature);
+  if (status == blink::WebOriginTrialTokenStatus::Success)
+    *feature_name = blink::WebString::fromUTF8(feature);
+  return status;
 }
 
 }  // namespace content