Changing confidence calculation to avoid div by zero

chrome/browser/autocomplete/network_action_predictor_unittest.cc

 // Copyright (c) 2011 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/autocomplete/network_action_predictor.h"
 
 #include "base/message_loop.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/autocomplete/autocomplete_match.h"
@@ skipping 29 matching lines @@
     string16 user_text;
     NetworkActionPredictor::Action expected_action;
   } test_url_db[] = {
     { GURL("http://www.testsite.com/a.html"),
       ASCIIToUTF16("Test - site - just a test"), 1, 1,
       ASCIIToUTF16("just"),
       NetworkActionPredictor::ACTION_PRERENDER },
     { GURL("http://www.testsite.com/b.html"),
       ASCIIToUTF16("Test - site - just a test"), 0, 1,
       ASCIIToUTF16("just"),
-      NetworkActionPredictor::ACTION_NONE },
+      NetworkActionPredictor::ACTION_PRERENDER },
     { GURL("http://www.testsite.com/c.html"),
       ASCIIToUTF16("Test - site - just a test"), 1, 5,
       ASCIIToUTF16("just"),
-      NetworkActionPredictor::ACTION_PRERENDER },
+      NetworkActionPredictor::ACTION_PRECONNECT },
     { GURL("http://www.testsite.com/d.html"),
       ASCIIToUTF16("Test - site - just a test"), 2, 5,
       ASCIIToUTF16("just"),
       NetworkActionPredictor::ACTION_PRERENDER },
     { GURL("http://www.testsite.com/e.html"),
       ASCIIToUTF16("Test - site - just a test"), 1, 8,
       ASCIIToUTF16("just"),
       NetworkActionPredictor::ACTION_PRECONNECT },
     { GURL("http://www.testsite.com/f.html"),
       ASCIIToUTF16("Test - site - just a test"), 4, 8,
       ASCIIToUTF16("just"),
       NetworkActionPredictor::ACTION_PRERENDER },
     { GURL("http://www.testsite.com/g.html"),
       ASCIIToUTF16("Test - site - just a test"), 1, 12,
       ASCIIToUTF16("just a"),
-      NetworkActionPredictor::ACTION_PRECONNECT },
+      NetworkActionPredictor::ACTION_NONE },
     { GURL("http://www.testsite.com/h.html"),
-      ASCIIToUTF16("Test - site - just a test"), 1, 21,
+      ASCIIToUTF16("Test - site - just a test"), 2, 21,
       ASCIIToUTF16("just a test"),
-      NetworkActionPredictor::ACTION_PRECONNECT },
+      NetworkActionPredictor::ACTION_NONE },
     { GURL("http://www.testsite.com/i.html"),
-      ASCIIToUTF16("Test - site - just a test"), 1, 28,
+      ASCIIToUTF16("Test - site - just a test"), 3, 28,
       ASCIIToUTF16("just a test"),
       NetworkActionPredictor::ACTION_NONE }
   };
 
   for (size_t i = 0; i < ARRAYSIZE_UNSAFE(test_url_db); ++i) {
     const base::Time visit_time =
         base::Time::Now() - base::TimeDelta::FromDays(
             test_url_db[i].days_from_now);
 
     history::URLRow row(test_url_db[i].url);
     row.set_title(test_url_db[i].title);
     row.set_typed_count(test_url_db[i].typed_count);
     row.set_last_visit(visit_time);
 
     CHECK(url_db->AddURL(row));
   }
 
   AutocompleteMatch match;
 
   for (size_t i = 0; i < ARRAYSIZE_UNSAFE(test_url_db); ++i) {
     match.destination_url = GURL(test_url_db[i].url);
     EXPECT_EQ(test_url_db[i].expected_action,
               predictor.RecommendAction(test_url_db[i].user_text, match))
         << "Unexpected action for " << match.destination_url;
   }
 }