[tracing] directly use memory-infra from blink -> base

third_party/WebKit/Source/platform/exported/Platform.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 31 matching lines @@
 }
 
 void Platform::initialize(Platform* platform)
 {
     s_platform = platform;
     if (s_platform)
         s_platform->m_mainThread = platform->currentThread();
 
     // TODO(ssid): remove this check after fixing crbug.com/486782.
     if (s_platform && s_platform->m_mainThread)
-        s_platform->registerMemoryDumpProvider(PartitionAllocMemoryDumpProvider::instance());
+        base::trace_event::MemoryDumpProvider::RegisterOnCurrentThread(PartitionAllocMemoryDumpProvider::instance());
 }
 
 void Platform::shutdown()
 {
     if (s_platform->m_mainThread)
-        s_platform->unregisterMemoryDumpProvider(PartitionAllocMemoryDumpProvider::instance());
+        base::trace_event::MemoryDumpProvider::Unregister(PartitionAllocMemoryDumpProvider::instance());
 
     if (s_platform)
         s_platform->m_mainThread = 0;
     s_platform = 0;
 }
 
 Platform* Platform::current()
 {
     return s_platform;
 }
 
 WebThread* Platform::mainThread() const
 {
     return m_mainThread;
 }
 
 } // namespace blink