Adjust memory sizes of persistent histogram allocations.

chrome/browser/chrome_browser_field_trials.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/chrome_browser_field_trials.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/feature_list.h"
@@ skipping 50 matching lines @@
     LOCAL_MEMORY_SUCCESS,
     LOCAL_MEMORY_FAILED,
     MAPPED_FILE_SUCCESS,
     MAPPED_FILE_FAILED,
     CREATE_ALLOCATOR_RESULTS
   };
   int result;
 
   // Create persistent/shared memory and allow histograms to be stored in
   // it. Memory that is not actualy used won't be physically mapped by the
-  // system. BrowserMetrics usage, as reported in UMA, peaked around 1.9MiB
-  // as of 2016-02-20.
-  const size_t kAllocSize = 3 << 20;     // 3 MiB
+  // system. BrowserMetrics usage, as reported in UMA, peaked around 3.0MiB
+  // as of 2016-12-20.
+  const size_t kAllocSize = 5 << 20;     // 5 MiB
   const uint32_t kAllocId = 0x935DDD43;  // SHA1(BrowserMetrics)
   std::string storage = variations::GetVariationParamValueByFeature(
       base::kPersistentHistogramsFeature, "storage");
   if (storage == "MappedFile") {
     // Create global allocator with the "active" file.
     base::GlobalHistogramAllocator::CreateWithFile(
         active_file, kAllocSize, kAllocId,
         ChromeMetricsServiceClient::kBrowserMetricsName);
     result = MAPPED_FILE_SUCCESS;
   } else if (storage == "LocalMemory") {
@@ skipping 62 matching lines @@
     bool has_seed,
     base::FeatureList* feature_list) {
   CreateFallbackSamplingTrialIfNeeded(has_seed, feature_list);
 }
 
 void ChromeBrowserFieldTrials::InstantiateDynamicTrials() {
   // Persistent histograms must be enabled as soon as possible.
   InstantiatePersistentHistograms();
   tracing::SetupBackgroundTracingFieldTrial();
 }