Run pre-classification checks in the browser before starting client-side phishing detection.

chrome/renderer/safe_browsing/phishing_classifier_delegate.h

Index: chrome/renderer/safe_browsing/phishing_classifier_delegate.h
diff --git a/chrome/renderer/safe_browsing/phishing_classifier_delegate.h b/chrome/renderer/safe_browsing/phishing_classifier_delegate.h
index 89788f2edabf7c3432610b1e33f7a3aa2ed1deba..7d2c0787277dcca4605258ab43b1ba1ab90c7fa0 100644
--- a/chrome/renderer/safe_browsing/phishing_classifier_delegate.h
+++ b/chrome/renderer/safe_browsing/phishing_classifier_delegate.h
@@ -34,7 +34,16 @@ class PhishingClassifierDelegate : public RenderViewObserver {
   void SetPhishingScorer(const safe_browsing::Scorer* scorer);
 
   // RenderViewObserver implementation, public for testing.
+
+  // Called by the RenderView once a page has finished loading.  Updates the
+  // last-loaded URL and page id, then starts classification if all other
+  // conditions are met (see MaybeStartClassification for details).
   virtual void PageCaptured(const string16& page_text);
+
+  // Called by the RenderView when a page has started loading in the given
+  // WebFrame.  Typically, this will cause any pending classification to be
+  // cancelled.  However, if the navigation is within the same page, we
+  // continue running the current classification.
   virtual void DidCommitProvisionalLoad(WebKit::WebFrame* frame,
                                         bool is_new_navigation);
 
@@ -48,34 +57,47 @@ class PhishingClassifierDelegate : public RenderViewObserver {
   // RenderViewObserver implementation.
   virtual bool OnMessageReceived(const IPC::Message& message);
 
+  // Called by the RenderView when it receives a StartPhishingDetection IPC
+  // from the browser.  This signals that it is ok to begin classification
+  // for the given toplevel URL.  If the URL has been fully loaded into the
+  // RenderView and a Scorer has been set, this will begin classification,
+  // otherwise classification will be deferred until these conditions are met.
+  void OnStartPhishingDetection(const GURL& url);
+
   // Called when classification for the current page finishes.
   void ClassificationDone(bool is_phishy, double phishy_score);
 
   // Returns the RenderView's toplevel URL, with the ref stripped.
   GURL StripToplevelUrl();
 
+  // Shared code to begin classification if all conditions are met.
+  void MaybeStartClassification();
+
   // The PhishingClassifier to use for the RenderView.  This is created once
   // a scorer is made available via SetPhishingScorer().
   scoped_ptr<PhishingClassifier> classifier_;
 
-  // The last URL that was sent to the phishing classifier.
-  GURL last_url_sent_to_classifier_;
+  // The last URL that the browser instructed us to classify.
+  GURL last_url_received_from_browser_;
+
+  // The last URL and page id that have finished loading in the RenderView.
+  // These correspond to the text in classifier_page_text_.
+  GURL last_finished_load_url_;
+  int32 last_finished_load_id_;
 
-  // The page id of the last load that was sent to the phishing classifier.
-  // This is used to suppress phishing classification on back and forward
-  // navigations in history.
+  // The URL and page id of the last load that we actually started
+  // classification on.  This is used to suppress phishing classification on
+  // subframe navigation and back and forward navigations in history.
+  GURL last_url_sent_to_classifier_;
   int32 last_page_id_sent_to_classifier_;
 
   // The page text that will be analyzed by the phishing classifier.  This is
   // set by OnNavigate and cleared when the classifier finishes.  Note that if
-  // there is no classifier yet when OnNavigate is called, the page text will
-  // be cached until the scorer is set and a classifier can be created.
+  // there is no Scorer yet when OnNavigate is called, or the browser has not
+  // instructed us to classify the page, the page text will be cached until
+  // these conditions are met.
   string16 classifier_page_text_;
 
-  // Set to true if we should run the phishing classifier on the current page
-  // as soon as SetPhishingScorer() is called.
-  bool pending_classification_;
-
   DISALLOW_COPY_AND_ASSIGN(PhishingClassifierDelegate);
 };