Clean up the unused Suggest field trial and make GetActiveSuggestFieldTrialHash

chrome/browser/omnibox/omnibox_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/omnibox/omnibox_field_trial.h"
 
 #include <string>
 
 #include "base/metrics/field_trial.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/strings/string_number_conversions.h"
 #include "chrome/common/metrics/metrics_util.h"
 #include "chrome/common/metrics/variations/variation_ids.h"
 #include "chrome/common/metrics/variations/variations_util.h"
 
 namespace {
 
 // Field trial names.
 const char kDisallowInlineHQPFieldTrialName[] = "OmniboxDisallowInlineHQP";
-// Because we regularly change the name of the suggest field trial in
-// order to shuffle users among groups, we use the date the current trial
-// was created as part of the name.
-const char kSuggestFieldTrialStarted2013Q1Name[] =
-    "OmniboxSearchSuggestTrialStarted2013Q1";
 const char kHQPNewScoringFieldTrialName[] = "OmniboxHQPNewScoringMax1400";
 const char kHUPCullRedirectsFieldTrialName[] = "OmniboxHUPCullRedirects";
 const char kHUPCreateShorterMatchFieldTrialName[] =
     "OmniboxHUPCreateShorterMatch";
 const char kHQPReplaceHUPScoringFieldTrialName[] =
     "OmniboxHQPReplaceHUPProhibitTrumpingInlineableResult";
 
 // The autocomplete dynamic field trial name prefix.  Each field trial is
 // configured dynamically and is retrieved automatically by Chrome during
 // the startup.
 const char kAutocompleteDynamicFieldTrialPrefix[] = "AutocompleteDynamicTrial_";
 // The maximum number of the autocomplete dynamic field trials (aka layers).
 const int kMaxAutocompleteDynamicFieldTrials = 5;
 
 // Field trial experiment probabilities.
 
 // For inline History Quick Provider field trial, put 0% ( = 0/100 )
 // of the users in the disallow-inline experiment group.
 const base::FieldTrial::Probability kDisallowInlineHQPFieldTrialDivisor = 100;
 const base::FieldTrial::Probability
     kDisallowInlineHQPFieldTrialExperimentFraction = 0;
 
-// For the search suggestion field trial, divide the people in the
-// trial into 20 equally-sized buckets.  The suggest provider backend
-// will decide what behavior (if any) to change based on the group.
-const int kSuggestFieldTrialNumberOfGroups = 20;
-
 // For History Quick Provider new scoring field trial, put 0% ( = 0/100 )
 // of the users in the new scoring experiment group.
 const base::FieldTrial::Probability kHQPNewScoringFieldTrialDivisor = 100;
 const base::FieldTrial::Probability
     kHQPNewScoringFieldTrialExperimentFraction = 0;
 
 // For HistoryURL provider cull redirects field trial, put 0% ( = 0/100 )
 // of the users in the don't-cull-redirects experiment group.
 // TODO(mpearson): Remove this field trial and the code it uses once I'm
 // sure it's no longer needed.
@@ skipping 70 matching lines @@
   // get ingrained, users tend to learn that a particular suggestion is
   // at a particular spot in the drop-down--we're going to make these
   // field trials sticky.  We want users to stay in them once assigned
   // so they have a better experience and also so we don't get weird
   // effects as omnibox ranking keeps changing and users learn they can't
   // trust the omnibox.
   trial->UseOneTimeRandomization();
   disallow_inline_hqp_experiment_group = trial->AppendGroup("DisallowInline",
       kDisallowInlineHQPFieldTrialExperimentFraction);
 
-  // Create the suggest field trial.
-  // Make it expire on September 1, 2013.
-  trial = base::FieldTrialList::FactoryGetFieldTrial(
-      kSuggestFieldTrialStarted2013Q1Name, kSuggestFieldTrialNumberOfGroups,
-      "0", 2013, 9, 1, NULL);
-  trial->UseOneTimeRandomization();
-
-  // Mark this group in suggest requests to Google.
-  chrome_variations::AssociateGoogleVariationID(
-      chrome_variations::GOOGLE_WEB_PROPERTIES,
-      kSuggestFieldTrialStarted2013Q1Name, "0",
-      chrome_variations::SUGGEST_TRIAL_STARTED_2013_Q1_ID_MIN);
-  DCHECK_EQ(kSuggestFieldTrialNumberOfGroups,
-      chrome_variations::SUGGEST_TRIAL_STARTED_2013_Q1_ID_MAX -
-      chrome_variations::SUGGEST_TRIAL_STARTED_2013_Q1_ID_MIN + 1);
-
-  // We've already created one group; now just need to create
-  // kSuggestFieldTrialNumGroups - 1 more. Mark these groups in
-  // suggest requests to Google.
-  for (int i = 1; i < kSuggestFieldTrialNumberOfGroups; i++) {
-    const std::string group_name = base::IntToString(i);
-    trial->AppendGroup(group_name, 1);
-    chrome_variations::AssociateGoogleVariationID(
-        chrome_variations::GOOGLE_WEB_PROPERTIES,
-        kSuggestFieldTrialStarted2013Q1Name, group_name,
-        static_cast<chrome_variations::VariationID>(
-            chrome_variations::SUGGEST_TRIAL_STARTED_2013_Q1_ID_MIN + i));
-  }
-
-  // Make sure that we participate in the suggest experiment by calling group()
-  // on the newly created field trial.  This is necessary to activate the field
-  // trial group as there are no more references to it within the Chrome code.
-  trial->group();
-
   // Create inline History Quick Provider new scoring field trial.
   // Make it expire on April 14, 2013.
   trial = base::FieldTrialList::FactoryGetFieldTrial(
       kHQPNewScoringFieldTrialName, kHQPNewScoringFieldTrialDivisor,
       "Standard", 2013, 4, 14, NULL);
   trial->UseOneTimeRandomization();
   hqp_new_scoring_experiment_group = trial->AppendGroup("NewScoring",
       kHQPNewScoringFieldTrialExperimentFraction);
 
   // Create the HistoryURL provider cull redirects field trial.
@@ skipping 72 matching lines @@
 bool OmniboxFieldTrial::InDisallowInlineHQPFieldTrialExperimentGroup() {
   if (!base::FieldTrialList::TrialExists(kDisallowInlineHQPFieldTrialName))
     return false;
 
   // Return true if we're in the experiment group.
   const int group = base::FieldTrialList::FindValue(
       kDisallowInlineHQPFieldTrialName);
   return group == disallow_inline_hqp_experiment_group;
 }
 
-bool OmniboxFieldTrial::GetActiveSuggestFieldTrialHash(
-    uint32* field_trial_hash) {
-  if (!base::FieldTrialList::TrialExists(kSuggestFieldTrialStarted2013Q1Name))
-    return false;
-
-  *field_trial_hash = metrics::HashName(kSuggestFieldTrialStarted2013Q1Name);
-  return true;
+bool OmniboxFieldTrial::GetActiveSuggestFieldTrialHashes(
+    std::vector<uint32>* field_trial_hashes) {

[Mark P, 2013/04/11 18:17:14]

Please explicitly clear it first.

[Bart N., 2013/04/11 19:35:07]

Done.

+  bool found = false;

[Mark P, 2013/04/11 18:17:14]

Rather having a found variable, consider returning !empty().

Or consider whether you need to return anything at all.

[Bart N., 2013/04/11 19:35:07]

Yes, much better now.

+  for (int i = 0; i < kMaxAutocompleteDynamicFieldTrials; ++i) {
+    const std::string& trial_name = DynamicFieldTrialName(i);
+    if (base::FieldTrialList::TrialExists(trial_name)) {
+      field_trial_hashes->push_back(metrics::HashName(trial_name));
+      found = true;
+    }
+  }
+  return found;
 }
 
 bool OmniboxFieldTrial::InHQPNewScoringFieldTrial() {
   return base::FieldTrialList::TrialExists(kHQPNewScoringFieldTrialName);
 }
 
 bool OmniboxFieldTrial::InHQPNewScoringFieldTrialExperimentGroup() {
   if (!InHQPNewScoringFieldTrial())
     return false;
 
@@ skipping 38 matching lines @@
 
 bool OmniboxFieldTrial::InHQPReplaceHUPScoringFieldTrialExperimentGroup() {
   if (!InHQPReplaceHUPScoringFieldTrial())
     return false;
 
   // Return true if we're in the experiment group.
   const int group = base::FieldTrialList::FindValue(
       kHQPReplaceHUPScoringFieldTrialName);
   return group == hqp_replace_hup_scoring_experiment_group;
 }