Mozart: Improve internal scene graph representation.

services/gfx/compositor/graph/scene_label.cc

Index: services/gfx/compositor/graph/scene_label.cc
diff --git a/services/gfx/compositor/graph/scene_label.cc b/services/gfx/compositor/graph/scene_label.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e4dfec019179a8d6c334a75077151f07d1d2e0fa
--- /dev/null
+++ b/services/gfx/compositor/graph/scene_label.cc
@@ -0,0 +1,38 @@
+// 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.
+
+#include "services/gfx/compositor/graph/scene_label.h"
+
+#include "base/strings/stringprintf.h"
+
+namespace compositor {
+
+SceneLabel::SceneLabel(uint32_t token, const std::string& label)
+    : token_(token), label_(label) {}
+
+SceneLabel::SceneLabel(const SceneLabel& other)
+    : token_(other.token_), label_(other.label_) {}
+
+SceneLabel::~SceneLabel() {}
+
+std::string SceneLabel::FormattedLabel() const {
+  return label_.empty() ? base::StringPrintf("<%d>", token_)
+                        : base::StringPrintf("<%d:%s>", token_, label_.c_str());
+}
+
+std::string SceneLabel::FormattedLabelForVersion(uint32_t version) const {
+  return label_.empty() ? base::StringPrintf("<%d/%d>", token_, version)
+                        : base::StringPrintf("<%d:%s/%d>", token_,
+                                             label_.c_str(), version);
+}
+
+std::string SceneLabel::FormattedLabelForNode(uint32_t version,
+                                              uint32_t node_id) const {
+  return label_.empty()
+             ? base::StringPrintf("<%d/%d>[%d]", token_, version, node_id)
+             : base::StringPrintf("<%d:%s/%d>[%d]", token_, label_.c_str(),
+                                  version, node_id);
+}
+
+}  // namespace compositor