Delete some VariationsService histograms that are not useful.

chrome/browser/metrics/variations/variations_service.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/metrics/variations/variations_service.h"
 
 #include <set>
 
 #include "base/build_time.h"
 #include "base/command_line.h"
@@ skipping 417 matching lines @@
           response_date,
           base::TimeDelta::FromMilliseconds(kServerTimeResolutionMs),
           latency);
     }
   }
 
   if (response_code != net::HTTP_OK) {
     DVLOG(1) << "Variations server request returned non-HTTP_OK response code: "
              << response_code;
     if (response_code == net::HTTP_NOT_MODIFIED) {
-      UMA_HISTOGRAM_MEDIUM_TIMES("Variations.FetchNotModifiedLatency", latency);
       RecordLastFetchTime();
       // Update the seed date value in local state (used for expiry check on
       // next start up), since 304 is a successful response.
       local_state_->SetInt64(prefs::kVariationsSeedDate,
                              response_date.ToInternalValue());
-    } else {
-      UMA_HISTOGRAM_MEDIUM_TIMES("Variations.FetchOtherLatency", latency);
     }
     return;
   }
-  UMA_HISTOGRAM_MEDIUM_TIMES("Variations.FetchSuccessLatency", latency);
 
   std::string seed_data;
   bool success = request->GetResponseAsString(&seed_data);
   DCHECK(success);
 
   std::string seed_signature;
   request->GetResponseHeaders()->EnumerateHeader(NULL,
                                                  "X-Seed-Signature",
                                                  &seed_signature);
   if (seed_store_.StoreSeedData(seed_data, seed_signature, response_date))
@@ skipping 18 matching lines @@
 
 void VariationsService::RecordLastFetchTime() {
   // local_state_ is NULL in tests, so check it first.
   if (local_state_) {
     local_state_->SetInt64(prefs::kVariationsLastFetchTime,
                            base::Time::Now().ToInternalValue());
   }
 }
 
 }  // namespace chrome_variations