Merge from Chromium at DEPS revision r205460

This commit was generated by merge_to_master.py.

Change-Id: I4a744a5e426bd3bb378d887cfa56fe054742a540
diff --git a/webkit/browser/dom_storage/dom_storage_namespace.h b/webkit/browser/dom_storage/dom_storage_namespace.h
new file mode 100644
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+++ b/webkit/browser/dom_storage/dom_storage_namespace.h
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+// Copyright (c) 2012 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 WEBKIT_BROWSER_DOM_STORAGE_DOM_STORAGE_NAMESPACE_H_
+#define WEBKIT_BROWSER_DOM_STORAGE_DOM_STORAGE_NAMESPACE_H_
+
+#include <map>
+
+#include "base/basictypes.h"
+#include "base/files/file_path.h"
+#include "base/memory/ref_counted.h"
+#include "webkit/storage/webkit_storage_export.h"
+
+class GURL;
+
+namespace dom_storage {
+
+class DomStorageArea;
+class DomStorageTaskRunner;
+class SessionStorageDatabase;
+
+// Container for the set of per-origin Areas.
+// See class comments for DomStorageContext for a larger overview.
+class WEBKIT_STORAGE_EXPORT DomStorageNamespace
+    : public base::RefCountedThreadSafe<DomStorageNamespace> {
+ public:
+  // Option for PurgeMemory.
+  enum PurgeOption {
+    // Purge unopened areas only.
+    PURGE_UNOPENED,
+
+    // Purge aggressively, i.e. discard cache even for areas that have
+    // non-zero open count.
+    PURGE_AGGRESSIVE,
+  };
+
+  // Constructor for a LocalStorage namespace with id of 0
+  // and an optional backing directory on disk.
+  DomStorageNamespace(const base::FilePath& directory,  // may be empty
+                      DomStorageTaskRunner* task_runner);
+
+  // Constructor for a SessionStorage namespace with a non-zero id and an
+  // optional backing on disk via |session_storage_database| (may be NULL).
+  DomStorageNamespace(int64 namespace_id,
+                      const std::string& persistent_namespace_id,
+                      SessionStorageDatabase* session_storage_database,
+                      DomStorageTaskRunner* task_runner);
+
+  int64 namespace_id() const { return namespace_id_; }
+  const std::string& persistent_namespace_id() const {
+    return persistent_namespace_id_;
+  }
+
+  // Returns the storage area for the given origin,
+  // creating instance if needed. Each call to open
+  // must be balanced with a call to CloseStorageArea.
+  DomStorageArea* OpenStorageArea(const GURL& origin);
+  void CloseStorageArea(DomStorageArea* area);
+
+  // Returns the area for |origin| if it's open, otherwise NULL.
+  DomStorageArea* GetOpenStorageArea(const GURL& origin);
+
+  // Creates a clone of |this| namespace including
+  // shallow copies of all contained areas.
+  // Should only be called for session storage namespaces.
+  DomStorageNamespace* Clone(int64 clone_namespace_id,
+                             const std::string& clone_persistent_namespace_id);
+
+  void DeleteLocalStorageOrigin(const GURL& origin);
+  void DeleteSessionStorageOrigin(const GURL& origin);
+  void PurgeMemory(PurgeOption purge);
+  void Shutdown();
+
+  unsigned int CountInMemoryAreas() const;
+
+ 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);
+    ~AreaHolder();
+  };
+  typedef std::map<GURL, AreaHolder> AreaMap;
+
+  ~DomStorageNamespace();
+
+  // Returns a pointer to the area holder in our map or NULL.
+  AreaHolder* GetAreaHolder(const GURL& origin);
+
+  int64 namespace_id_;
+  std::string persistent_namespace_id_;
+  base::FilePath directory_;
+  AreaMap areas_;
+  scoped_refptr<DomStorageTaskRunner> task_runner_;
+  scoped_refptr<SessionStorageDatabase> session_storage_database_;
+};
+
+}  // namespace dom_storage
+
+
+#endif  // WEBKIT_BROWSER_DOM_STORAGE_DOM_STORAGE_NAMESPACE_H_