SafeBrowsing: Create a custom histogram enum for V4 GetHash results.

components/safe_browsing_db/v4_protocol_manager.h

 // Copyright 2016 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_SAFE_BROWSING_DB_V4_PROTOCOL_MANAGER_H_
 #define COMPONENTS_SAFE_BROWSING_DB_V4_PROTOCOL_MANAGER_H_
 
 // A class that implements Chrome's interface with the SafeBrowsing V4 protocol.
 //
 // The SafeBrowsingV4ProtocolManager handles formatting and making requests of,
@@ skipping 68 matching lines @@
                              FullHashCallback callback);
 
   // Retrieve the full hash and API metadata for a set of prefixes, and invoke
   // the callback argument when the results are retrieved. The callback may be
   // invoked synchronously. Uses the V4 Safe Browsing protocol.
   virtual void GetFullHashesWithApis(const std::vector<SBPrefix>& prefixes,
                                      FullHashCallback callback);
 
   // Enumerate failures for histogramming purposes.  DO NOT CHANGE THE
   // ORDERING OF THESE VALUES.
-  // TODO(kcarattini): Use a custom v4 histogram set.
   enum ResultType {
     // 200 response code means that the server recognized the hash
-    // prefix, while 204 is an empty response indicating that the
-    // server did not recognize it.
-    GET_HASH_STATUS_200,
-    GET_HASH_STATUS_204,
-
-    // Subset of successful responses which returned no full hashes.
-    // This includes the STATUS_204 case, and the *_ERROR cases.
-    GET_HASH_FULL_HASH_EMPTY,
-
-    // Subset of successful responses for which one or more of the
-    // full hashes matched (should lead to an interstitial).
-    GET_HASH_FULL_HASH_HIT,
-
-    // Subset of successful responses which weren't empty and have no
-    // matches.  It means that there was a prefix collision which was
-    // cleared up by the full hashes.
-    GET_HASH_FULL_HASH_MISS,
+    // prefix.
+    GET_HASH_STATUS_200 = 0,
 
     // Subset of successful responses where the response body wasn't parsable.
-    GET_HASH_PARSE_ERROR,
+    GET_HASH_PARSE_ERROR = 1,
 
     // Gethash request failed (network error).
-    GET_HASH_NETWORK_ERROR,
+    GET_HASH_NETWORK_ERROR = 2,
 
-    // Gethash request returned HTTP result code other than 200 or 204.
-    GET_HASH_HTTP_ERROR,
+    // Gethash request returned HTTP result code other than 200.
+    GET_HASH_HTTP_ERROR = 3,
 
     // Gethash attempted during error backoff, no request sent.
-    GET_HASH_BACKOFF_ERROR,
+    GET_HASH_BACKOFF_ERROR = 4,
 
     // Gethash attempted before min wait duration elapsed, no request sent.
-    GET_HASH_MIN_WAIT_DURATION_ERROR,
+    GET_HASH_MIN_WAIT_DURATION_ERROR = 5,
 
     // Memory space for histograms is determined by the max.  ALWAYS
     // ADD NEW VALUES BEFORE THIS ONE.
-    GET_HASH_RESULT_MAX
+    GET_HASH_RESULT_MAX = 6
   };
 
   // Record a V4 GetHash result.
   static void RecordGetHashResult(ResultType result_type);
 
   // Record HTTP response code when there's no error in fetching an HTTP
   // request, and the error code, when there is.
   // |metric_name| is the name of the UMA metric to record the response code or
   // error code against, |status| represents the status of the HTTP request, and
   // |response code| represents the HTTP response code received from the server.
@@ skipping 142 matching lines @@
       net::URLRequestContextGetter* request_context_getter,
       const V4ProtocolConfig& config) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(V4ProtocolManagerFactory);
 };
 
 }  // namespace safe_browsing
 
 #endif  // COMPONENTS_SAFE_BROWSING_DB_V4_PROTOCOL_MANAGER_H_