Add a field trial for using lower sqlite cache sizes.

chrome/browser/history/in_memory_database.cc

 // Copyright (c) 2011 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/history/in_memory_database.h"
 
 #include "base/file_path.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "build/build_config.h"
+#include "chrome/browser/history/history_field_trial.h"
 
 namespace history {
 
 InMemoryDatabase::InMemoryDatabase() : URLDatabase() {
 }
 
 InMemoryDatabase::~InMemoryDatabase() {
 }
 
 bool InMemoryDatabase::InitDB() {
@@ skipping 61 matching lines @@
   }
 
   // Copy URL data to memory.
   base::TimeTicks begin_load = base::TimeTicks::Now();
   if (!db_.Execute(
       "INSERT INTO urls SELECT * FROM history.urls WHERE typed_count > 0")) {
     // Unable to get data from the history database. This is OK, the file may
     // just not exist yet.
   }
   base::TimeTicks end_load = base::TimeTicks::Now();
-  UMA_HISTOGRAM_MEDIUM_TIMES("History.InMemoryDBPopulate",
-                             end_load - begin_load);
+  UMA_HISTOGRAM_MEDIUM_TIMES(
+      "History.InMemoryDBPopulate" + HistoryFieldTrial::GetGroupSuffix(),
+      end_load - begin_load);
   UMA_HISTOGRAM_COUNTS("History.InMemoryDBItemCount", db_.GetLastChangeCount());
 
   {
     // This calculation should be fast (since it's on an in-memory DB with
     // an average of only 35 rows).
     sql::Statement visit_count(db_.GetUniqueStatement(
         "SELECT sum(visit_count) FROM urls"));
     if (visit_count && visit_count.Step()) {
       UMA_HISTOGRAM_COUNTS("History.InMemoryTypedUrlVisitCount",
                            visit_count.ColumnInt(0));
@@ skipping 42 matching lines @@
   CreateKeywordSearchTermsIndices();
 
   return true;
 }
 
 sql::Connection& InMemoryDatabase::GetDB() {
   return db_;
 }
 
 }  // namespace history