Move WebCacheMemoryDumpProvider to platform

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 "public/platform/WebProcessMemoryDump.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