Adding more histograms to ResourcePrefetchPredictor.

chrome/browser/prerender/prerender_field_trial.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/prerender/prerender_field_trial.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
@@ skipping 256 matching lines @@
           kSpeculativePrefetchingLearningTrialName,
           kDivisor,
           "SpeculativePrefetchingLearningEnabled",
           2012, 12, 30,
           &g_speculative_prefetching_learning_default_group_number));
   speculative_prefetching_learning_trial->AppendGroup(
       "SpeculativePrefetchingDisabled",
       kDisabledProbability);
 }
 
-bool IsSpeculativeResourcePrefetchingLearningEnabled(Profile* profile) {
-  if (!profile)

[dominich, 2012/08/30 18:25:23]

this might mean that tests with NULL profiles will be entered into a field
trial. I'm not sure if the FieldTrial code already checks that for tests, or if
you're manually setting the commandline switch for all tests to disabled, but
it's something to be aware of.

[Shishir, 2012/08/30 18:48:09]

Digging a little deeper, I need to disable this when the profile is off the
record. This could be the reason I am seeing so many empty databases.  So I
think I will have to put this profile check back in.

-    return false;
-
+bool IsSpeculativeResourcePrefetchingLearningEnabled() {
   // Override any field trial groups if the user has set a command line flag.
   if (CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kSpeculativeResourcePrefetching)) {
     const std::string switch_value =
         CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
             switches::kSpeculativeResourcePrefetching);
 
     return switch_value == switches::kSpeculativeResourcePrefetchingLearning;
   }
 
   const int group = FieldTrialList::FindValue(
       kSpeculativePrefetchingLearningTrialName);
   return group == g_speculative_prefetching_learning_default_group_number;
 }
 
 }  // namespace prerender