WIP add code to check http headers for origin trial tokens

content/common/origin_trials/trial_token_validator.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/common/origin_trials/trial_token_validator.h"
 
 #include "base/time/time.h"
 #include "content/common/origin_trials/trial_token.h"
 #include "content/public/common/content_client.h"
+#include "net/http/http_response_headers.h"
+#include "net/url_request/url_request.h"
 
 namespace content {
 
 bool TrialTokenValidator::ValidateToken(const std::string& token,
                                         const url::Origin& origin,
                                         base::StringPiece featureName) {
   scoped_ptr<TrialToken> trial_token = TrialToken::Parse(token);
 
   ContentClient* content_client = GetContentClient();
   CHECK(content_client);
   base::StringPiece public_key = content_client->GetOriginTrialPublicKey();
   return !public_key.empty() && trial_token &&
          trial_token->IsAppropriate(origin, featureName) &&
          trial_token->IsValid(base::Time::Now(), public_key);
 }
 
+bool TrialTokenValidator::RequestEnablesFeature(const net::URLRequest* request,
+                                                base::StringPiece featureName) {
+  url::Origin origin(request->url());
+  size_t iter = 0;
+  std::string token;
+  while (request->response_headers()->EnumerateHeader(&iter, "Origin-Trial",
+                                                      &token)) {
+    if (ValidateToken(token, origin, featureName))
+      return true;
+  }
+  return false;
+}
+
 }  // namespace content