Use base::Callback in Quota related code.

webkit/database/database_quota_client.h

Index: webkit/database/database_quota_client.h
diff --git a/webkit/database/database_quota_client.h b/webkit/database/database_quota_client.h
index fb37ff6150a6034788b8f6f211864fc0e51ff70e..b9fed41efe83daee2ba95d22c213dfc049eef50d 100644
--- a/webkit/database/database_quota_client.h
+++ b/webkit/database/database_quota_client.h
@@ -34,15 +34,15 @@ class DatabaseQuotaClient : public quota::QuotaClient,
   virtual void OnQuotaManagerDestroyed();
   virtual void GetOriginUsage(const GURL& origin_url,
                               quota::StorageType type,
-                              GetUsageCallback* callback) OVERRIDE;
+                              const GetUsageCallback& callback) OVERRIDE;
   virtual void GetOriginsForType(quota::StorageType type,
-                                 GetOriginsCallback* callback) OVERRIDE;
+                                 const GetOriginsCallback& callback) OVERRIDE;
   virtual void GetOriginsForHost(quota::StorageType type,
                                  const std::string& host,
-                                 GetOriginsCallback* callback)  OVERRIDE;
+                                 const GetOriginsCallback& callback)  OVERRIDE;
   virtual void DeleteOriginData(const GURL& origin,
                                 quota::StorageType type,
-                                DeletionCallback* callback) OVERRIDE;
+                                const DeletionCallback& callback) OVERRIDE;
  private:
   class HelperTask;
   class GetOriginUsageTask;
@@ -52,17 +52,17 @@ class DatabaseQuotaClient : public quota::QuotaClient,
   class DeleteOriginTask;
 
   typedef quota::CallbackQueueMap1
-      <GetUsageCallback*,
+      <GetUsageCallback,
        GURL,  // origin
        int64
       > UsageForOriginCallbackMap;
   typedef quota::CallbackQueue2
-      <GetOriginsCallback*,
+      <GetOriginsCallback,
        const std::set<GURL>&,
        quota::StorageType
       > OriginsForTypeCallbackQueue;
   typedef quota::CallbackQueueMap2
-      <GetOriginsCallback*,
+      <GetOriginsCallback,
        std::string,  // host
        const std::set<GURL>&,
        quota::StorageType