Omnibox: Add Mid-Input Matching to HistoryQuick Provider

chrome/browser/autocomplete/autocomplete_field_trial.cc

Index: chrome/browser/autocomplete/autocomplete_field_trial.cc
diff --git a/chrome/browser/autocomplete/autocomplete_field_trial.cc b/chrome/browser/autocomplete/autocomplete_field_trial.cc
index 412936e77793066d4798d957b025974020113f7c..08e5410129479853e04e27d4825e3c719939a836 100644
--- a/chrome/browser/autocomplete/autocomplete_field_trial.cc
+++ b/chrome/browser/autocomplete/autocomplete_field_trial.cc
@@ -32,6 +32,8 @@ static const char kHQPReplaceHUPScoringFieldTrialName[] =
     "OmniboxHQPReplaceHUPHostFix";
 static const char kHQPOnlyCountMatchesAtWordBoundariesFieldTrialName[] =
     "OmniboxHQPOnlyCountMatchesAtWordBoundaries";
+static const char kHQPUseCursorPositionFieldTrialName[] =
+    "OmniboxHQPUseCursorPosition";
 
 // The autocomplete dynamic field trial name prefix.  Each field trial is
 // configured dynamically and is retrieved automatically by Chrome during
@@ -93,6 +95,13 @@ const base::FieldTrial::Probability
 const base::FieldTrial::Probability
     kHQPOnlyCountMatchesAtWordBoundariesFieldTrialExperimentFraction = 0;
 
+// For the field trial that allows HistoryQuick provider to use the
+// cursor position, put 25% ( = 25/100 ) of the users in the experiment group.
+const base::FieldTrial::Probability
+    kHQPUseCursorPositionFieldTrialDivisor = 100;
+const base::FieldTrial::Probability
+    kHQPUseCursorPositionFieldTrialExperimentFraction = 25;
+
 
 // Field trial IDs.
 // Though they are not literally "const", they are set only once, in
@@ -124,6 +133,10 @@ int hqp_replace_hup_scoring_experiment_group = 0;
 // word boundaries experiment group.
 int hqp_only_count_matches_at_word_boundaries_experiment_group = 0;
 
+// Field trial ID for the HistoryQuick provider use cursor position
+// experiment group.
+int hqp_use_cursor_position_experiment_group = 0;
+
 }
 
 
@@ -233,6 +246,17 @@ void AutocompleteFieldTrial::ActivateStaticTrials() {
       trial->AppendGroup("HQPOnlyCountMatchesAtWordBoundaries",
           kHQPOnlyCountMatchesAtWordBoundariesFieldTrialExperimentFraction);
 
+  // Create the field trial that allows HistoryQuick provider to break
+  // omnibox inputs at the cursor position.  Make it expire on August 23, 2013.
+  trial = base::FieldTrialList::FactoryGetFieldTrial(
+      kHQPUseCursorPositionFieldTrialName,
+      kHQPUseCursorPositionFieldTrialDivisor,
+      "Standard", 2013, 8, 23, NULL);
+  trial->UseOneTimeRandomization();
+  hqp_use_cursor_position_experiment_group =
+      trial->AppendGroup("HQPUseCursorPosition",
+          kHQPUseCursorPositionFieldTrialExperimentFraction);
+
   static_field_trials_initialized = true;
 }
 
@@ -340,3 +364,18 @@ bool AutocompleteFieldTrial::
       kHQPOnlyCountMatchesAtWordBoundariesFieldTrialName);
   return group == hqp_only_count_matches_at_word_boundaries_experiment_group;
 }
+
+bool AutocompleteFieldTrial::InHQPUseCursorPositionFieldTrial() {
+  return base::FieldTrialList::TrialExists(kHQPUseCursorPositionFieldTrialName);
+}
+
+bool AutocompleteFieldTrial::
+    InHQPUseCursorPositionFieldTrialExperimentGroup() {
+  if (!InHQPUseCursorPositionFieldTrial())
+    return false;
+
+  // Return true if we're in the experiment group.
+  const int group = base::FieldTrialList::FindValue(
+      kHQPUseCursorPositionFieldTrialName);
+  return group == hqp_use_cursor_position_experiment_group;
+}