Delete Tracked, and move Location to its own file.

base/location.h

Index: base/location.h
diff --git a/base/location.h b/base/location.h
new file mode 100644
index 0000000000000000000000000000000000000000..fab8f4f54738ed792be68eed9829612bec085e75
--- /dev/null
+++ b/base/location.h
@@ -0,0 +1,80 @@
+// Copyright (c) 2011 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 BASE_LOCATION_H_
+#define BASE_LOCATION_H_
+
+#include <string>
+
+#include "base/base_export.h"
+
+#ifndef NDEBUG
+#ifndef TRACK_ALL_TASK_OBJECTS
+#define TRACK_ALL_TASK_OBJECTS
+#endif   // TRACK_ALL_TASK_OBJECTS
+#endif  // NDEBUG
+
+namespace tracked_objects {
+
+// Location provides basic info where of an object was constructed, or was
+// significantly brought to life.
+class BASE_EXPORT Location {
+ public:
+  // Constructor should be called with a long-lived char*, such as __FILE__.
+  // It assumes the provided value will persist as a global constant, and it
+  // will not make a copy of it.
+  Location(const char* function_name,
+           const char* file_name,
+           int line_number,
+           const void* program_counter);
+
+  // Provide a default constructor for easy of debugging.
+  Location();
+
+  // Comparison operator for insertion into a std::map<> hash tables.
+  // All we need is *some* (any) hashing distinction.  Strings should already
+  // be unique, so we don't bother with strcmp or such.
+  // Use line number as the primary key (because it is fast, and usually gets us
+  // a difference), and then pointers as secondary keys (just to get some
+  // distinctions).
+  bool operator < (const Location& other) const {
+    if (line_number_ != other.line_number_)
+      return line_number_ < other.line_number_;
+    if (file_name_ != other.file_name_)
+      return file_name_ < other.file_name_;
+    return function_name_ < other.function_name_;
+  }
+
+  const char* function_name()   const { return function_name_; }
+  const char* file_name()       const { return file_name_; }
+  int line_number()             const { return line_number_; }
+  const void* program_counter() const { return program_counter_; }
+
+  std::string ToString() const;
+
+  void Write(bool display_filename, bool display_function_name,
+             std::string* output) const;
+
+  // Write function_name_ in HTML with '<' and '>' properly encoded.
+  void WriteFunctionName(std::string* output) const;
+
+ private:
+  const char* const function_name_;
+  const char* const file_name_;
+  const int line_number_;
+  const void* const program_counter_;
+};
+
+BASE_EXPORT const void* GetProgramCounter();
+
+// Define a macro to record the current source location.
+#define FROM_HERE tracked_objects::Location(                                   \
+    __FUNCTION__,                                                              \
+    __FILE__,                                                                  \
+    __LINE__,                                                                  \
+    tracked_objects::GetProgramCounter())                                      \
+
+}  // namespace tracked_objects
+
+#endif  // BASE_LOCATION_H_