Don't demote top match for certain match types.

BUG=

Review URL: https://codereview.chromium.org/55413002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232979 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 66 insertions, 1 deletions

diff --git a/chrome/browser/omnibox/omnibox_field_trial.cc b/chrome/browser/omnibox/omnibox_field_trial.cc
index e2c7144..6b9510b 100644
--- a/chrome/browser/omnibox/omnibox_field_trial.cc
+++ b/chrome/browser/omnibox/omnibox_field_trial.cc
@@ -254,7 +254,7 @@ void OmniboxFieldTrial::GetDemotionsByType(
     for (base::StringPairs::const_iterator it = kv_pairs.begin();
          it != kv_pairs.end(); ++it) {
       // This is a best-effort conversion; we trust the hand-crafted parameters
-      // downloaded from the server to be perfect.  There's no need for handle
+      // downloaded from the server to be perfect.  There's no need to handle
       // errors smartly.
       int k, v;
       base::StringToInt(it->first, &k);
@@ -265,6 +265,32 @@ void OmniboxFieldTrial::GetDemotionsByType(
   }
 }
 
+OmniboxFieldTrial::UndemotableTopMatchTypes
+OmniboxFieldTrial::GetUndemotableTopTypes(
+    AutocompleteInput::PageClassification current_page_classification) {
+  UndemotableTopMatchTypes undemotable_types;
+  const std::string types_rule =
+      OmniboxFieldTrial::GetValueForRuleInContext(
+          kUndemotableTopTypeRule,
+          current_page_classification);
+  // The value of the UndemotableTopTypes rule is a comma-separated list of
+  // AutocompleteMatchType::Type enums represented as an integer. The
+  // DemoteByType rule does not apply to the top match if the type of the top
+  // match is in this list.
+  std::vector<std::string> types;
+  base::SplitString(types_rule, ',', &types);
+  for (std::vector<std::string>::const_iterator it = types.begin();
+       it != types.end(); ++it) {
+    // This is a best-effort conversion; we trust the hand-crafted parameters
+    // downloaded from the server to be perfect.  There's no need to handle
+    // errors smartly.
+    int t;
+    base::StringToInt(*it, &t);
+    undemotable_types.insert(static_cast<AutocompleteMatchType::Type>(t));
+  }
+  return undemotable_types;
+}
+
 bool OmniboxFieldTrial::ReorderForLegalDefaultMatch(
     AutocompleteInput::PageClassification current_page_classification) {
   return OmniboxFieldTrial::GetValueForRuleInContext(
@@ -278,6 +304,7 @@ const char OmniboxFieldTrial::kShortcutsScoringMaxRelevanceRule[] =
     "ShortcutsScoringMaxRelevance";
 const char OmniboxFieldTrial::kSearchHistoryRule[] = "SearchHistory";
 const char OmniboxFieldTrial::kDemoteByTypeRule[] = "DemoteByType";
+const char OmniboxFieldTrial::kUndemotableTopTypeRule[] = "UndemotableTopTypes";
 const char OmniboxFieldTrial::kReorderForLegalDefaultMatchRule[] =
     "ReorderForLegalDefaultMatch";
 const char OmniboxFieldTrial::kReorderForLegalDefaultMatchRuleEnabled[] =
diff --git a/chrome/browser/omnibox/omnibox_field_trial.h b/chrome/browser/omnibox/omnibox_field_trial.h
index 50b8701..1c9f80e 100644
--- a/chrome/browser/omnibox/omnibox_field_trial.h
+++ b/chrome/browser/omnibox/omnibox_field_trial.h
@@ -6,6 +6,7 @@
 #define CHROME_BROWSER_OMNIBOX_OMNIBOX_FIELD_TRIAL_H_
 
 #include <map>
+#include <set>
 #include <string>
 #include <vector>
 
@@ -22,6 +23,9 @@ class OmniboxFieldTrial {
   // given number.  Omitted types are assumed to have multipliers of 1.0.
   typedef std::map<AutocompleteMatchType::Type, float> DemotionMultipliers;
 
+  // A set of types that should not be demoted when they are the top match.
+  typedef std::set<AutocompleteMatchType::Type> UndemotableTopMatchTypes;
+
   // Creates the static field trial groups.
   // *** MUST NOT BE CALLED MORE THAN ONCE. ***
   static void ActivateStaticTrials();
@@ -148,6 +152,11 @@ class OmniboxFieldTrial {
       AutocompleteInput::PageClassification current_page_classification,
       DemotionMultipliers* demotions_by_type);
 
+  // Get the set of types that should not be demoted if they are the top
+  // match.
+  static UndemotableTopMatchTypes GetUndemotableTopTypes(
+      AutocompleteInput::PageClassification current_page_classification);
+
   // ---------------------------------------------------------
   // For the ReorderForLegalDefaultMatch experiment that's part of the
   // bundled omnibox field trial.
@@ -168,6 +177,7 @@ class OmniboxFieldTrial {
   static const char kShortcutsScoringMaxRelevanceRule[];
   static const char kSearchHistoryRule[];
   static const char kDemoteByTypeRule[];
+  static const char kUndemotableTopTypeRule[];
   static const char kReorderForLegalDefaultMatchRule[];
   // Rule values.
   static const char kReorderForLegalDefaultMatchRuleEnabled[];
diff --git a/chrome/browser/omnibox/omnibox_field_trial_unittest.cc b/chrome/browser/omnibox/omnibox_field_trial_unittest.cc
index 82522b6..edf222b 100644
--- a/chrome/browser/omnibox/omnibox_field_trial_unittest.cc
+++ b/chrome/browser/omnibox/omnibox_field_trial_unittest.cc
@@ -188,6 +188,34 @@ TEST_F(OmniboxFieldTrialTest, GetDemotionsByTypeWithFallback) {
   VerifyDemotion(demotions_by_type, AutocompleteMatchType::HISTORY_URL, 0.25);
 }
 
+TEST_F(OmniboxFieldTrialTest, GetUndemotableTopTypes) {
+  {
+    std::map<std::string, std::string> params;
+    const std::string rule(OmniboxFieldTrial::kUndemotableTopTypeRule);
+    params[rule + ":1:*"] = "1,3";
+    params[rule + ":3:*"] = "5";
+    params[rule + ":*:*"] = "2";
+    ASSERT_TRUE(chrome_variations::AssociateVariationParams(
+        OmniboxFieldTrial::kBundledExperimentFieldTrialName, "A", params));
+  }
+  base::FieldTrialList::CreateFieldTrial(
+      OmniboxFieldTrial::kBundledExperimentFieldTrialName, "A");
+  OmniboxFieldTrial::UndemotableTopMatchTypes undemotable_types;
+  undemotable_types = OmniboxFieldTrial::GetUndemotableTopTypes(
+      AutocompleteInput::NEW_TAB_PAGE);
+  ASSERT_EQ(2u, undemotable_types.size());
+  ASSERT_EQ(1u, undemotable_types.count(AutocompleteMatchType::HISTORY_URL));
+  ASSERT_EQ(1u, undemotable_types.count(AutocompleteMatchType::HISTORY_BODY));
+  undemotable_types = OmniboxFieldTrial::GetUndemotableTopTypes(
+      AutocompleteInput::HOME_PAGE);
+  ASSERT_EQ(1u, undemotable_types.size());
+  ASSERT_EQ(1u, undemotable_types.count(AutocompleteMatchType::NAVSUGGEST));
+  undemotable_types = OmniboxFieldTrial::GetUndemotableTopTypes(
+      AutocompleteInput::BLANK);
+  ASSERT_EQ(1u, undemotable_types.size());
+  ASSERT_EQ(1u, undemotable_types.count(AutocompleteMatchType::HISTORY_TITLE));
+}
+
 TEST_F(OmniboxFieldTrialTest, GetValueForRuleInContext) {
   // This test starts with Instant Extended off (the default state), then
   // enables Instant Extended and tests again on the same rules.