[Sync] Implement MemoryDumpProvider.

sql/connection.h

 // 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.
 
 #ifndef SQL_CONNECTION_H_
 #define SQL_CONNECTION_H_
 
 #include <stddef.h>
 #include <stdint.h>
 #include <map>
@@ skipping 10 matching lines @@
 #include "base/threading/thread_restrictions.h"
 #include "base/time/time.h"
 #include "sql/sql_export.h"
 
 struct sqlite3;
 struct sqlite3_stmt;
 
 namespace base {
 class FilePath;
 class HistogramBase;
+namespace trace_event {
+class MemoryAllocatorDump;
+}
 }
 
 namespace sql {
 
 class ConnectionMemoryDumpProvider;
 class Recovery;
 class Statement;
 
 // To allow some test classes to be friended.
 namespace test {
@@ skipping 203 matching lines @@
 
   // Runs "PRAGMA quick_check" and, unlike the FullIntegrityCheck method,
   // interprets the results returning true if the the statement executes
   // without error and results in a single "ok" value.
   bool QuickIntegrityCheck() WARN_UNUSED_RESULT;
 
   // Meant to be called from a client error callback so that it's able to
   // get diagnostic information about the database.
   std::string GetDiagnosticInfo(int extended_error, Statement* statement);
 
+  // Reports memory usage into provided memory dump.
+  bool ReportMemoryUsage(base::trace_event::MemoryAllocatorDump* mad);
+
   // Initialization ------------------------------------------------------------
 
   // Initializes the SQL connection for the given file, returning true if the
   // file could be opened. You can call this or OpenInMemory.
   bool Open(const base::FilePath& path) WARN_UNUSED_RESULT;
 
   // Initializes the SQL connection for a temporary in-memory database. There
   // will be no associated file on disk, and the initial database will be
   // empty. You can call this or Open.
   bool OpenInMemory() WARN_UNUSED_RESULT;
@@ skipping 554 matching lines @@
 
   // Stores the dump provider object when db is open.
   std::unique_ptr<ConnectionMemoryDumpProvider> memory_dump_provider_;
 
   DISALLOW_COPY_AND_ASSIGN(Connection);
 };
 
 }  // namespace sql
 
 #endif  // SQL_CONNECTION_H_