Add a term feature extractor for client-side phishing detection.

chrome/renderer/safe_browsing/phishing_dom_feature_extractor.h

 // Copyright (c) 2010 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.
 //
 // PhishingDOMFeatureExtractor handles computing DOM-based features for the
 // client-side phishing detection model.  These include the presence of various
 // types of elements, ratios of external and secure links, and tokens for
 // external domains linked to.
 
 #ifndef CHROME_RENDERER_SAFE_BROWSING_PHISHING_DOM_FEATURE_EXTRACTOR_H_
@@ skipping 31 matching lines @@
   // ownership of the clock.
   PhishingDOMFeatureExtractor(RenderView* render_view,
                               FeatureExtractorClock* clock);
   ~PhishingDOMFeatureExtractor();
 
   // Begins extracting features into the given FeatureMap for the page
   // currently loaded in this object's RenderView.  To avoid blocking the
   // render thread for too long, the feature extractor may run in several
   // chunks of work, posting a task to the current MessageLoop to continue
   // processing.  Once feature extraction is complete, |done_callback|
-  // is run.  PhishingDOMFeatureExtractor takes ownership of the callback.
+  // is run on the current thread.  PhishingDOMFeatureExtractor takes
+  // ownership of the callback.
   void ExtractFeatures(FeatureMap* features, DoneCallback* done_callback);
 
   // Cancels any pending feature extraction.  The DoneCallback will not be run.
   // Must be called if there is a feature extraction in progress when the page
   // is unloaded or the PhishingDOMFeatureExtractor is destroyed.
   void CancelPendingExtraction();
 
  private:
   struct FrameData;
   struct PageFeatureState;
 
-  // The maximum amount of time that we will spend on a single extraction
+  // The maximum amount of wall time that we will spend on a single extraction
   // iteration before pausing to let other MessageLoop tasks run.
   static const int kMaxTimePerChunkMs;
 
   // The number of elements that we will process before checking to see whether
   // kMaxTimePerChunkMs has elapsed.  Since checking the current time can be
   // slow, we don't do this on every element processed.
   static const int kClockCheckGranularity;
 
   // The maximum total amount of time that the feature extractor will run
   // before giving up on the current page.
@@ skipping 64 matching lines @@
   // Used to create ExtractFeaturesWithTimeout tasks.
   // These tasks are revoked if extraction is cancelled.
   ScopedRunnableMethodFactory<PhishingDOMFeatureExtractor> method_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PhishingDOMFeatureExtractor);
 };
 
 }  // namespace safe_browsing
 
 #endif  // CHROME_RENDERER_SAFE_BROWSING_PHISHING_DOM_FEATURE_EXTRACTOR_H_