Purge in-memory localStorage areas if the # of areas exceeds the limit

webkit/dom_storage/dom_storage_namespace.h

Index: webkit/dom_storage/dom_storage_namespace.h
diff --git a/webkit/dom_storage/dom_storage_namespace.h b/webkit/dom_storage/dom_storage_namespace.h
index 78ef4d77ff10b690dd39f97b569f17e4686a4632..1d20e8638d973dc437dfd4f49503fd41c7da91dd 100644
--- a/webkit/dom_storage/dom_storage_namespace.h
+++ b/webkit/dom_storage/dom_storage_namespace.h
@@ -25,6 +25,16 @@ class SessionStorageDatabase;
 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
@@ -59,9 +69,11 @@ class WEBKIT_STORAGE_EXPORT DomStorageNamespace
 
   void DeleteLocalStorageOrigin(const GURL& origin);
   void DeleteSessionStorageOrigin(const GURL& origin);
-  void PurgeMemory();
+  void PurgeMemory(PurgeOption purge);
   void Shutdown();
 
+  unsigned int CountInMemoryAreas() const;
+
  private:
   friend class base::RefCountedThreadSafe<DomStorageNamespace>;