Add a browsertest suite for net predictor

chrome/browser/net/predictor.cc

 // Copyright (c) 2012 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 "chrome/browser/net/predictor.h"
 
 #include <algorithm>
 #include <cmath>
 #include <set>
 #include <sstream>
@@ skipping 448 matching lines @@
 void Predictor::LearnFromNavigation(const GURL& referring_url,
                                     const GURL& target_url) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   if (!predictor_enabled_ || !CanPreresolveAndPreconnect())
     return;
   DCHECK_EQ(referring_url, Predictor::CanonicalizeUrl(referring_url));
   DCHECK_NE(referring_url, GURL::EmptyGURL());
   DCHECK_EQ(target_url, Predictor::CanonicalizeUrl(target_url));
   DCHECK_NE(target_url, GURL::EmptyGURL());
 
+  if (observer_) {
+    observer_->OnLearnFromNavigation(referring_url, target_url);
+  }

[mmenke, 2016/04/15 15:44:02]

nit:  Don't use braces on two-line ifs.

[Charlie Harrison, 2016/04/20 12:36:42]

Done.

   referrers_[referring_url].SuggestHost(target_url);
   // Possibly do some referrer trimming.
   TrimReferrers();
 }
 
 //-----------------------------------------------------------------------------
 // This section supports the about:dns page.
 
 void Predictor::PredictorGetHtmlInfo(Predictor* predictor,
                                      std::string* output) {
@@ skipping 826 matching lines @@
 }
 
 void SimplePredictor::ShutdownOnUIThread() {
   SetShutdown(true);
 }
 
 bool SimplePredictor::CanPrefetchAndPrerender() const { return true; }
 bool SimplePredictor::CanPreresolveAndPreconnect() const { return true; }
 
 }  // namespace chrome_browser_net