Add ostream helpers for FX String classes.

testing/fx_string_testhelpers.cpp

+// Copyright 2014 PDFium 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 "fx_string_testhelpers.h"
+
+#include <ios>
+#include <iomanip>
+
+namespace {
+
+template <typename T>
+std::ostream& output_string(std::ostream& out, const T& str) {
+  out << std::hex << std::setfill('0') << '"';
+  for (size_t i = 0; i < str.GetLength(); ++i) {
+    unsigned int c = str.GetAt(i);
+    if (c >= 0x20 && c < 0x7F) {
+      out << static_cast<char>(c);
+    } else if (sizeof(typename T::value_type) == 1) {
+      out << "\\x" << std::setw(2) << c << std::setw(0);
+    } else if (c < 0x10000) {
+      out << "\\u" << std::setw(4) << c << std::setw(0);
+    } else {
+      out << "<invalid>";
+    }
+  }
+  out << '"' << std::dec << std::setfill(' ');
+  return out;
+}
+
+}  // namespace
+
+std::ostream& operator<<(std::ostream& out, const CFX_ByteStringC& str) {
+  return output_string(out, str);
+}
+
+std::ostream& operator<<(std::ostream& out, const CFX_ByteString& str) {
+  return output_string(out, str);
+}
+
+std::ostream& operator<<(std::ostream& out, const CFX_WideStringC& str) {
+  return output_string(out, str);
+}
+
+std::ostream& operator<<(std::ostream& out, const CFX_WideString& str) {
+  return output_string(out, str);
+}