Moving platform tracing things into platform/tracing.

third_party/WebKit/Source/platform/MemoryCacheDumpProvider.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 MemoryCacheDumpProvider_h
-#define MemoryCacheDumpProvider_h
-
-#include "base/trace_event/memory_dump_provider.h"
-#include "base/trace_event/process_memory_dump.h"
-#include "platform/PlatformExport.h"
-#include "platform/heap/Handle.h"
-#include "platform/web_process_memory_dump.h"
-#include "wtf/Allocator.h"
-
-namespace blink {
-
-class PLATFORM_EXPORT MemoryCacheDumpClient : public GarbageCollectedMixin {
- public:
-  virtual ~MemoryCacheDumpClient() {}
-  virtual bool onMemoryDump(WebMemoryDumpLevelOfDetail,
-                            WebProcessMemoryDump*) = 0;
-
-  DECLARE_VIRTUAL_TRACE();
-};
-
-// This class is wrapper around MemoryCache to take memory snapshots. It dumps
-// the stats of cache only after the cache is created.
-class PLATFORM_EXPORT MemoryCacheDumpProvider final
-    : public base::trace_event::MemoryDumpProvider {
-  USING_FAST_MALLOC(MemoryCacheDumpProvider);
-
- public:
-  // This class is singleton since there is a global MemoryCache object.
-  static MemoryCacheDumpProvider* instance();
-  ~MemoryCacheDumpProvider() override;
-
-  // base::trace_event::MemoryDumpProvider implementation.
-  bool OnMemoryDump(const base::trace_event::MemoryDumpArgs&,
-                    base::trace_event::ProcessMemoryDump*) override;
-
-  void setMemoryCache(MemoryCacheDumpClient* client) {
-    DCHECK(isMainThread());
-    m_client = client;
-  }
-
- private:
-  MemoryCacheDumpProvider();
-
-  WeakPersistent<MemoryCacheDumpClient> m_client;
-
-  WTF_MAKE_NONCOPYABLE(MemoryCacheDumpProvider);
-};
-
-}  // namespace blink
-
-#endif  // MemoryCacheDumpProvider_h