Consolidate most of net/'s icu_string_conversions.h dependencies.

net/base/net_string_util_icu.cc

+// 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.
+
+#include "net/base/net_string_util.h"
+
+#include "base/i18n/i18n_constants.h"
+#include "base/i18n/icu_string_conversions.h"
+#include "base/strings/string_util.h"
+#include "third_party/icu/source/common/unicode/ucnv.h"
+
+namespace net {
+
+bool ConvertToUtf8(const std::string& text, const char* charset,
+                   std::string* output) {
+  UErrorCode err = U_ZERO_ERROR;
+  UConverter* converter(ucnv_open(charset, &err));
+  output->clear();
+  if (U_FAILURE(err))
+    return false;
+
+  // A single byte in a legacy encoding can be expanded to 3 bytes in UTF-8.
+  // A 'two-byte character' in a legacy encoding can be expanded to 4 bytes
+  // in UTF-8. Therefore, the expansion ratio is 3 at most. Add one for a
+  // trailing '\0'.
+  size_t output_length = text.length() * 3 + 1;
+  char* buf = WriteInto(output, output_length);

[mef, 2014/04/28 19:19:51]

could it return NULL?

[mmenke, 2014/04/28 19:29:18]

No, see
https://code.google.com/p/chromium/codesearch#chromium/src/base/strings/strin...

+  output_length = ucnv_toAlgorithmic(UCNV_UTF8, converter, buf, output_length,
+                                     text.data(), text.length(), &err);
+  ucnv_close(converter);
+  if (U_FAILURE(err)) {
+    output->clear();
+    return false;
+  }
+  output->resize(output_length);
+  return true;
+}
+
+bool ConvertToUtf8AndNormalize(const std::string& text, const char* charset,
+                               std::string* output) {
+  return base::ConvertToUtf8AndNormalize(text,  charset, output);
+}
+
+bool ConvertLatin1ToUtf8AndNormalize(const std::string& text,
+                                    std::string* output) {
+  return net::ConvertToUtf8AndNormalize(text,  base::kCodepageLatin1, output);
+}
+
+bool ConvertToUTF16(const std::string& text, const char* charset,
+                    base::string16* output) {
+  return base::CodepageToUTF16(text, charset,
+                               base::OnStringConversionError::FAIL, output);
+}
+
+bool ConvertLatin1ToUTF16(const std::string& text, base::string16* output) {
+  return base::CodepageToUTF16(text, base::kCodepageLatin1,
+                               base::OnStringConversionError::FAIL, output);
+}
+
+}  // namespace net