Mozart: Ensure time always runs forward.

services/gfx/compositor/graph/scene_label.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 SERVICES_GFX_COMPOSITOR_GRAPH_SCENE_LABEL_H_
 #define SERVICES_GFX_COMPOSITOR_GRAPH_SCENE_LABEL_H_
 
 #include <string>
 
 namespace compositor {
 
 // Convenience class for formatting descriptive labels for diagnostics.
 class SceneLabel {
  public:
   SceneLabel(uint32_t token, const std::string& label);
   SceneLabel(const SceneLabel& other);
   ~SceneLabel();
 
   // Gets the scene token.
   uint32_t token() const { return token_; }
 
   // Gets the user-supplied label of the scene.
   const std::string& label() const { return label_; }
 
   // Gets a descriptive label including optional version and node information.
   std::string FormattedLabel() const;
-  std::string FormattedLabelForVersion(uint32_t version) const;
-  std::string FormattedLabelForNode(uint32_t version, uint32_t node_id) const;
+  std::string FormattedLabelForVersion(uint32_t version,
+                                       int64_t presentation_time) const;
+  std::string FormattedLabelForNode(uint32_t version,
+                                    int64_t presentation_time,
+                                    uint32_t node_id) const;
 
  private:
   uint32_t const token_;
   std::string const label_;
 };
 
 }  // namespace compositor
 
 #endif  // SERVICES_GFX_COMPOSITOR_GRAPH_SCENE_LABEL_H_