[Sync] Implement MemoryDumpProvider.

sql/connection_memory_dump_provider.h

 // Copyright 2015 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_MEMORY_DUMP_PROVIDER_H
 #define SQL_CONNECTION_MEMORY_DUMP_PROVIDER_H
 
 #include <string>
 
 #include "base/macros.h"
 #include "base/synchronization/lock.h"
+#include "base/trace_event/memory_allocator_dump.h"
 #include "base/trace_event/memory_dump_provider.h"
 
 struct sqlite3;
 
 namespace sql {
 
 class ConnectionMemoryDumpProvider
     : public base::trace_event::MemoryDumpProvider {
  public:
   ConnectionMemoryDumpProvider(sqlite3* db, const std::string& name);
   ~ConnectionMemoryDumpProvider() override;
 
   void ResetDatabase();
 
   // base::trace_event::MemoryDumpProvider implementation.
   bool OnMemoryDump(
       const base::trace_event::MemoryDumpArgs& args,
       base::trace_event::ProcessMemoryDump* process_memory_dump) override;
 
+  // Reports memory usage into provided memory dump.
+  // Called by sql::Connection when its owner asks it to report memory usage.
+  bool ReportMemoryUsage(base::trace_event::MemoryAllocatorDump* mad);
+
  private:
+  bool GetDbMemoryUsage(int* cache_size,
+                        int* schema_size,
+                        int* statement_size);
+
+  std::string FormatDumpName() const;
+
   sqlite3* db_;  // not owned.
   base::Lock lock_;
   std::string connection_name_;
 
   DISALLOW_COPY_AND_ASSIGN(ConnectionMemoryDumpProvider);
 };
 
 }  // namespace sql
 
 #endif  // SQL_CONNECTION_MEMORY_DUMP_PROVIDER_H