1 files changed, 31 insertions, 0 deletions
diff --git a/chromium/tools/clang/blink_gc_plugin/NeedsTracing.h b/chromium/tools/clang/blink_gc_plugin/NeedsTracing.h
new file mode 100644
index 00000000000..cf4c2c1f70a
--- /dev/null
+++ b/chromium/tools/clang/blink_gc_plugin/NeedsTracing.h
@@ -0,0 +1,31 @@
+// Copyright 2014 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.
+
+// NeedsTracing is a three-point value ordered by unneeded < unknown < needed.
+// Unneeded means that the point definitively does not need to be traced.
+
+#ifndef TOOLS_BLINK_GC_PLUGIN_NEEDS_TRACING_H_
+#define TOOLS_BLINK_GC_PLUGIN_NEEDS_TRACING_H_
+
+class NeedsTracing {
+ public:
+  static NeedsTracing Unneeded() { return kUnneeded; }
+  static NeedsTracing Unknown() { return kUnknown; }
+  static NeedsTracing Needed() { return kNeeded; }
+  bool IsUnneeded() { return value_ == kUnneeded; }
+  bool IsUnknown() { return value_ == kUnknown; }
+  bool IsNeeded() { return value_ == kNeeded; }
+  NeedsTracing LUB(const NeedsTracing& other) {
+    return value_ > other.value_ ? value_ : other.value_;
+  }
+  bool operator==(const NeedsTracing& other) {
+    return value_ == other.value_;
+  }
+ private:
+  enum Value { kUnneeded, kUnknown, kNeeded };
+  NeedsTracing(Value value) : value_(value) {}
+  Value value_;
+};
+
+#endif // TOOLS_BLINK_GC_PLUGIN_NEEDS_TRACING_H_