Proposal: Provide the ability to monitor the usage of origins

webkit/browser/quota/quota_manager.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 WEBKIT_BROWSER_QUOTA_QUOTA_MANAGER_H_
 #define WEBKIT_BROWSER_QUOTA_QUOTA_MANAGER_H_
 
 #include <deque>
 #include <list>
 #include <map>
 #include <set>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/sequenced_task_runner_helpers.h"
 #include "webkit/browser/quota/quota_callbacks.h"
 #include "webkit/browser/quota/quota_client.h"
 #include "webkit/browser/quota/quota_database.h"
 #include "webkit/browser/quota/quota_task.h"
 #include "webkit/browser/quota/special_storage_policy.h"
+#include "webkit/browser/quota/storage_observer.h"
 #include "webkit/browser/webkit_storage_browser_export.h"
 
 namespace base {
 class FilePath;
 class SequencedTaskRunner;
 class SingleThreadTaskRunner;
 }
 
 namespace quota_internals {
 class QuotaInternalsProxy;
@@ skipping 180 matching lines @@
     return special_storage_policy_.get() &&
            special_storage_policy_->CanQueryDiskSize(origin);
   }
 
   virtual void GetOriginsModifiedSince(StorageType type,
                                        base::Time modified_since,
                                        const GetOriginsCallback& callback);
 
   bool ResetUsageTracker(StorageType type);
 
+  // Used to register/deregister observers that wish to monitor storage events.
+  void AddStorageObserver(const StorageObserver::MonitorParams& params,

[tmdiep, 2014/03/17 06:27:08]

If we need the ability to update the params for an observer, we can rename this
function and have it perform both add and update.

[nhiroki, 2014/03/17 06:51:40]

From the viewpoint of the Quota spec, I think we don't need the ability because
StorageWatcher is immutable.

+                          StorageObserver* observer);
+  void RemoveStorageObserver(StorageObserver* observer);
+
   // Determines the portion of the temp pool that can be
   // utilized by a single host (ie. 5 for 20%).
   static const int kPerHostTemporaryPortion;
 
   static const int64 kPerHostPersistentQuotaLimit;
 
   static const char kDatabaseName[];
 
   static const int64 kMinimumPreserveForSystem;
 
@@ skipping 194 matching lines @@
 
 struct QuotaManagerDeleter {
   static void Destruct(const QuotaManager* manager) {
     manager->DeleteOnCorrectThread();
   }
 };
 
 }  // namespace quota
 
 #endif  // WEBKIT_BROWSER_QUOTA_QUOTA_MANAGER_H_