Add a new entry to omnibox_event.proto to log specific type of contextual suggestions

components/omnibox/browser/omnibox_field_trial.h

 // Copyright 2014 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.
 
 #ifndef COMPONENTS_OMNIBOX_BROWSER_OMNIBOX_FIELD_TRIAL_H_
 #define COMPONENTS_OMNIBOX_BROWSER_OMNIBOX_FIELD_TRIAL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 115 matching lines @@
 
   // Do not change these values as they need to be in sync with values
   // specified in experiment configs on the variations server.
   enum EmphasizeTitlesCondition {
     EMPHASIZE_WHEN_NONEMPTY = 0,
     EMPHASIZE_WHEN_TITLE_MATCHES = 1,
     EMPHASIZE_WHEN_ONLY_TITLE_MATCHES = 2,
     EMPHASIZE_NEVER = 3
   };
 
+  struct ContextualZeroSuggest {
+    enum Type {
+      NOT_SET = 0,
+      COOCCURENCE_PAGE = 1,
+      HIVEMIND_URL = 2,
+      LOCAL_STORE_MAP = 3,
+      LOCAL_STORE_WEBPAGE = 4,
+      LOCAL_STORE_RESERVATION = 5,
+      MOVIE_REVIEW = 6,
+      MOVIE_SHOWTIME = 7,
+      ON_THE_NEWS = 8,
+      POPULAR_DOMAINS = 9,
+      SIMILAR_PAGES = 10,
+      TOP_ENTITY_INFO = 11,
+      OTHER = 12,
+      NUM_TYPES,
+    };
+
+    // Converts |type| to a string representation.
+    static std::string ToString(const Type& type);
+
+    // Converts |type| from a string representation to Type.
+    static Type FromString(const std::string& type);
+
+    // Records the given type to the
+    // ZeroSuggest.ContextualSuggestType.SuggestionProvided histogram.
+    static void RecordTypeAsProvided(const std::string& type);
+
+    // Records the given type to the
+    // ZeroSuggest.ContextualSuggestType.SuggestionUsed histogram.
+    static void RecordTypeAsUsed(const std::string& type);
+  };
+
   // ---------------------------------------------------------
   // For any experiment that's part of the bundled omnibox field trial.
 
   // Returns a bitmap containing AutocompleteProvider::Type values
   // that should be disabled in AutocompleteController.
   static int GetDisabledProviderTypes();
 
   // Returns whether the user is in any dynamic field trial where the
   // group has a the prefix |group_prefix|.
   static bool HasDynamicFieldTrialGroupPrefix(const char *group_prefix);
@@ skipping 362 matching lines @@
   // prioritize different wildcard contexts, see the implementation.  How to
   // interpret the value is left to the caller; this is rule-dependent.
   static std::string GetValueForRuleInContext(
       const std::string& rule,
       metrics::OmniboxEventProto::PageClassification page_classification);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(OmniboxFieldTrial);
 };
 
 #endif  // COMPONENTS_OMNIBOX_BROWSER_OMNIBOX_FIELD_TRIAL_H_