Delete blimp/helium and remove references to it from dependent targets

blimp/helium/update_scheduler.h

-// Copyright 2016 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 BLIMP_HELIUM_UPDATE_SCHEDULER_H_
-#define BLIMP_HELIUM_UPDATE_SCHEDULER_H_
-
-#include "base/callback.h"
-#include "blimp/helium/blimp_helium_export.h"
-
-namespace blimp {
-
-namespace proto {
-class HeliumMessage;
-}  // namespace proto
-
-namespace helium {
-
-class ObjectSyncState;
-class StreamPump {
- public:
-  virtual ~StreamPump() = default;
-
-  virtual void OnMessageAvailable() = 0;
-};
-
-// TODO(steimel): #include sync_manager.h instead once it's ready.
-using HeliumObjectId = uint32_t;
-
-// The UpdateScheduler is responsible for determining the next message to be
-// sent on each Stream. This primarily means choosing a dirty object to pull the
-// next Changeset from and generating acknowledgement messages for received
-// Changesets.
-class BLIMP_HELIUM_EXPORT UpdateScheduler {
- public:
-  using MessagePreparedCallback = base::Callback<void(proto::HeliumMessage)>;
-
-  virtual ~UpdateScheduler() = default;
-
-  // Adds/Removes objects bound to the Stream for which this instance schedules
-  // updates. |object| should not be destroyed before calling RemoveObject().
-  virtual void AddObject(HeliumObjectId object_id, ObjectSyncState* object) = 0;
-  virtual void RemoveObject(HeliumObjectId object_id) = 0;
-
-  // Called by StreamPump to determine if the UpdateScheduler has data to send.
-  virtual bool HasMessageReady() const = 0;
-
-  // Called by StreamPump to request next HeliumMessage.
-  virtual void PrepareMessage(MessagePreparedCallback callback) = 0;
-
-  // Called by the ObjectSyncState when an object is updated locally.
-  // Note that this may be called (e.g. on Stream connection) when an object is
-  // first registered with the UpdateScheduler, to force it to check for pending
-  // changes.
-  virtual void OnLocalUpdate(HeliumObjectId object_id) = 0;
-
-  // Called by the ObjectSyncState when an object processes a Changeset, to
-  // schedule acknowledgement.
-  virtual void OnNeedsAck(HeliumObjectId object_id) = 0;
-
-  // Associates |pump| with this instance and informs each ObjectSyncState of
-  // the new connection. |pump| should not be destroyed before this instance.
-  virtual void OnStreamConnected(StreamPump* pump) = 0;
-
-  // Creates an UpdateScheduler instance.
-  static std::unique_ptr<UpdateScheduler> Create();
-};
-
-}  // namespace helium
-}  // namespace blimp
-
-#endif  // BLIMP_HELIUM_UPDATE_SCHEDULER_H_