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

blimp/helium/version_vector.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_VERSION_VECTOR_H_
-#define BLIMP_HELIUM_VERSION_VECTOR_H_
-
-#include <stdint.h>
-
-#include "blimp/common/proto/helium.pb.h"
-#include "blimp/helium/blimp_helium_export.h"
-#include "blimp/helium/syncable_common.h"
-
-namespace blimp {
-namespace helium {
-
-// Version Vectors are used to store revisions of both client and engine
-// objects. It will allow determining partial ordering between 2 VersionVectors.
-//
-// It's similar to a vector clock, but it different according to the Wikipedia
-// definition specially when handling merge. Vector Clocks specifies you should
-// advance your local version, whereas VersionVectors you won't advance your
-// local version (Unless you have to handle a merge conflict and requires to
-// send data to the other side).
-
-typedef uint64_t Revision;
-
-class BLIMP_HELIUM_EXPORT VersionVector {
- public:
-  enum class Comparison { LessThan, EqualTo, GreaterThan, Conflict };
-
-  VersionVector(Revision local_revision, Revision remote_revision);
-  VersionVector();
-  VersionVector(const VersionVector&) = default;
-
-  // Compares two vector clocks. There are 4 possibilities for the result:
-  // * LessThan: One revision is equal and for the other is smaller.
-  // (1,0).CompareTo((2, 0));
-  // * EqualTo: Both revisions are the same.
-  // * GreaterThan: One revision is equal and for the other is greater.
-  // (2,0).CompareTo((1, 0));
-  // * Conflict: Both revisions are different. (1,0).CompareTo(0,1)
-  Comparison CompareTo(const VersionVector& other) const;
-
-  // Compares two vector clocks with special handling for conflict cases.
-  // If |this| and |other| are in conflict, then the value of |bias| determines
-  // whether the local VersionVector wins (returned as GreaterThan), or loses
-  // (returned as LessThan).
-  Comparison CompareWithBias(const VersionVector& other, Bias bias) const;
-
-  // Merges two vector clocks. This function should be used at synchronization
-  // points. i.e. when client receives data from the server or vice versa.
-  VersionVector MergeWith(const VersionVector& other) const;
-
-  // Increments local_revision_ by one. This is used when something changes
-  // in the local state like setting a property or applying a change set with
-  // a conflict that requires sending state to the other peer.
-  void IncrementLocal();
-
-  Revision local_revision() const { return local_revision_; }
-
-  void set_local_revision(Revision local_revision) {
-    local_revision_ = local_revision;
-  }
-
-  Revision remote_revision() const { return remote_revision_; }
-
-  void set_remote_revision(Revision remote_revision) {
-    remote_revision_ = remote_revision;
-  }
-
-  // Create the proto message corresponding to this object.
-  proto::VersionVectorMessage ToProto() const;
-
-  // Inverts the local and remote components respectively.
-  // Used when we send VersionVector across the wire. The local becomes
-  // remote and vice versa.
-  VersionVector Invert() const;
-
- private:
-  Revision local_revision_ = 0;
-  Revision remote_revision_ = 0;
-};
-
-}  // namespace helium
-}  // namespace blimp
-
-#endif  // BLIMP_HELIUM_VERSION_VECTOR_H_