[tracing] Add a memory dump provider for DOM storage

content/browser/dom_storage/dom_storage_namespace.h

 // Copyright 2013 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 CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_NAMESPACE_H_
 #define CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_NAMESPACE_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <string>
 
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 #include "url/gurl.h"
 
+namespace base {
+namespace trace_event {
+class ProcessMemoryDump;
+}
+}
+
 namespace content {
 
 class DOMStorageArea;
 class DOMStorageTaskRunner;
 class SessionStorageDatabase;
 
 // Container for the set of per-origin Areas.
 // See class comments for DOMStorageContextImpl for a larger overview.
 class CONTENT_EXPORT DOMStorageNamespace
     : public base::RefCountedThreadSafe<DOMStorageNamespace> {
@@ skipping 41 matching lines @@
                              const std::string& clone_persistent_namespace_id);
 
   void DeleteLocalStorageOrigin(const GURL& origin);
   void DeleteSessionStorageOrigin(const GURL& origin);
   void PurgeMemory(PurgeOption purge);
   void Shutdown();
   void Flush();
 
   unsigned int CountInMemoryAreas() const;
 
+  // Adds memory statistics to |pmd| for chrome://tracing.
+  void OnMemoryDump(base::trace_event::ProcessMemoryDump* pmd);
+
  private:
   friend class base::RefCountedThreadSafe<DOMStorageNamespace>;
 
   // Struct to hold references to our contained areas and
   // to keep track of how many tabs have a given area open.
   struct AreaHolder {
     scoped_refptr<DOMStorageArea> area_;
     int open_count_;
     AreaHolder();
     AreaHolder(DOMStorageArea* area, int count);
@@ skipping 12 matching lines @@
   base::FilePath directory_;
   AreaMap areas_;
   scoped_refptr<DOMStorageTaskRunner> task_runner_;
   scoped_refptr<SessionStorageDatabase> session_storage_database_;
 };
 
 }  // namespace content
 
 
 #endif  // CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_NAMESPACE_H_