Use a direct include of utf_string_conversions.h in android_webview/, apps/, ash/, base/.

base/strings/string_number_conversions_unittest.cc

 // Copyright (c) 2012 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 <errno.h>
 #include <math.h>
 
 #include <limits>
 
 #include "base/strings/string_number_conversions.h"
-#include "base/utf_string_conversions.h"
+#include "base/strings/utf_string_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 
 namespace {
 
 template <typename INT>
 struct IntToStringTest {
   INT num;
   const char* sexpected;
@@ skipping 477 matching lines @@
 
 TEST(StringNumberConversionsTest, HexEncode) {
   std::string hex(HexEncode(NULL, 0));
   EXPECT_EQ(hex.length(), 0U);
   unsigned char bytes[] = {0x01, 0xff, 0x02, 0xfe, 0x03, 0x80, 0x81};
   hex = HexEncode(bytes, sizeof(bytes));
   EXPECT_EQ(hex.compare("01FF02FE038081"), 0);
 }
 
 }  // namespace base