Move dmg_fp to base/third_party/dmg_fp and include the

base/third_party/dmg_fp/dmg_fp.h

+// Copyright (c) 2008 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 THIRD_PARTY_DMG_FP_H_
+#define THIRD_PARTY_DMG_FP_H_
+
+namespace dmg_fp {
+
+// Return a nearest machine number to the input decimal
+// string (or set errno to ERANGE). With IEEE arithmetic, ties are
+// broken by the IEEE round-even rule.  Otherwise ties are broken by
+// biased rounding (add half and chop).
+double strtod(const char* s00, char** se);
+
+// Convert double to ASCII string. For meaning of parameters
+// see dtoa.cc file.
+char* dtoa(double d, int mode, int ndigits,
+           int* decpt, int* sign, char** rve);
+
+// Must be used to free values returned by dtoa.
+void freedtoa(char* s);
+
+// Store the closest decimal approximation to x in b.
+char* g_fmt(char* b, double x);
+
+}  // namespace dmg_fp
+
+#endif  // THIRD_PARTY_DMG_FP_H_