Added memory limit for chrome.activityLogPrivate returned results

chrome/browser/extensions/activity_log/counting_policy.cc

 // Copyright 2013 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.
 
 // A policy for storing activity log data to a database that performs
 // aggregation to reduce the size of the database.  The database layout is
 // nearly the same as FullStreamUIPolicy, which stores a complete log, with a
 // few changes:
 //   - a "count" column is added to track how many log records were merged
 //     together into this row
@@ skipping 424 matching lines @@
     where_next = " AND ";
   }
   if (!page_url.empty()) {
     where_str += where_next + "page_url LIKE ?";
     where_next = " AND ";
   }
   if (!arg_url.empty())
     where_str += where_next + "arg_url LIKE ?";
   std::string query_str = base::StringPrintf(
       "SELECT extension_id,time, action_type, api_name, args, page_url,"
-      "page_title, arg_url, other, count FROM %s WHERE %s ORDER BY time DESC",
+      "page_title, arg_url, other, count FROM %s WHERE %s ORDER BY count DESC "
+      "LIMIT 300",
       kReadViewName,
       where_str.c_str());
   sql::Statement query(db->GetUniqueStatement(query_str.c_str()));
   int i = -1;
   if (!extension_id.empty())
     query.BindString(++i, extension_id);
   if (!api_name.empty())
     query.BindString(++i, api_name);
   if (type != Action::ACTION_ANY)
     query.BindInt(++i, static_cast<int>(type));
@@ skipping 263 matching lines @@
   return true;
 }
 
 void CountingPolicy::Close() {
   // The policy object should have never been created if there's no DB thread.
   DCHECK(BrowserThread::IsMessageLoopValid(BrowserThread::DB));
   ScheduleAndForget(activity_database(), &ActivityDatabase::Close);
 }
 
 }  // namespace extensions