Add integration of the new heuristics

components/dom_distiller/core/page_features.h

 // Copyright 2015 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.
 
 #ifndef COMPONENTS_DOM_DISTILLER_CORE_PAGE_FEATURES_H_
 #define COMPONENTS_DOM_DISTILLER_CORE_PAGE_FEATURES_H_
 
 #include <vector>
 
 #include "base/values.h"
 #include "url/gurl.h"
 
 namespace dom_distiller {
 
+// The length of the derived features vector.
+extern int kDerivedFeaturesCount;
+
 // The distillable page detector is a model trained on a list of numeric
 // features derived from core more complex features of a webpage (like the
 // body's .textContent). This derives the numeric features for a set of core
 // features.
 //
 // Note: It is crucial that these features are derived in the same way and are
 // in the same order as in the training pipeline. See //heuristics/distillable
 // in the external DomDistillerJs repo.
 std::vector<double> CalculateDerivedFeatures(bool isOGArticle,
                                              const GURL& url,
                                              double numElements,
                                              double numAnchors,
                                              double numForms,
                                              const std::string& innerText,
                                              const std::string& textContent,
                                              const std::string& innerHTML);
 
 // Calculates the derived features from the JSON value as returned by the
 // javascript core feature extraction.
-std::vector<double> CalculateDerivedFeaturesFromJSON(const base::Value* json);
+std::vector<double> CalculateDerivedFeaturesFromJSON(
+    const base::Value* stringified_json);
 
 }  // namespace dom_distiller
 
 #endif  // COMPONENTS_DOM_DISTILLER_CORE_PAGE_FEATURES_H_