Revert of Make IP Address related functions return the empty string when used on an invalid address.

net/base/ip_address_number.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 "net/base/ip_address_number.h"
 
 #include <limits.h>
 
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 85 matching lines @@
 
 std::string IPAddressToString(const uint8_t* address, size_t address_len) {
   std::string str;
   url::StdStringCanonOutput output(&str);
 
   if (address_len == kIPv4AddressSize) {
     url::AppendIPv4Address(address, &output);
   } else if (address_len == kIPv6AddressSize) {
     url::AppendIPv6Address(address, &output);
   } else {
-    return std::string();
+    CHECK(false) << "Invalid IP address with length: " << address_len;
   }
 
   output.Complete();
   return str;
 }
 
 std::string IPAddressToStringWithPort(const uint8_t* address,
                                       size_t address_len,
                                       uint16_t port) {
   std::string address_str = IPAddressToString(address, address_len);
-  if (address_str.empty())
-    return address_str;
 
   if (address_len == kIPv6AddressSize) {
     // Need to bracket IPv6 addresses since they contain colons.
     return base::StringPrintf("[%s]:%d", address_str.c_str(), port);
   }
   return base::StringPrintf("%s:%d", address_str.c_str(), port);
 }
 
 std::string IPAddressToString(const IPAddressNumber& addr) {
   return IPAddressToString(&addr.front(), addr.size());
@@ skipping 163 matching lines @@
   }
   return a1.size() * CHAR_BIT;
 }
 
 unsigned MaskPrefixLength(const IPAddressNumber& mask) {
   IPAddressNumber all_ones(mask.size(), 0xFF);
   return CommonPrefixLength(mask, all_ones);
 }
 
 }  // namespace net