Changed QuotaManager to be refcounted in QuotaDispatcherHost

Bug: 800349
Change-Id: I4555b66e001907803ec47597cdc2111cc62807bd
Reviewed-on: https://chromium-review.googlesource.com/895230Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Sasha Morrissey <sashab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533892}

content/browser/quota_dispatcher_host.h

@@ -82,7 +82,7 @@ class QuotaDispatcherHost : public blink::mojom::QuotaDispatcherHost {
   // The ID of this render frame, MSG_ROUTING_NONE for workers.
   const int render_frame_id_;
 
-  storage::QuotaManager* quota_manager_;
+  scoped_refptr<storage::QuotaManager> quota_manager_;
   scoped_refptr<QuotaPermissionContext> permission_context_;
 
   base::WeakPtrFactory<QuotaDispatcherHost> weak_factory_;