Migrate net/proxy/* to net::IPAddress.

net/base/ip_address.cc

Index: net/base/ip_address.cc
diff --git a/net/base/ip_address.cc b/net/base/ip_address.cc
index 606483b0bf65f829fc67f31a8b46eb83aa6600a1..71ae18bc3a29f32060800fec6c743109c11d7973 100644
--- a/net/base/ip_address.cc
+++ b/net/base/ip_address.cc
@@ -4,6 +4,9 @@
 
 #include "net/base/ip_address.h"
 
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_piece.h"
+#include "base/strings/string_split.h"
 #include "net/base/ip_address_number.h"
 #include "url/gurl.h"
 #include "url/url_canon_ip.h"
@@ -139,6 +142,36 @@ bool IPAddressMatchesPrefix(const IPAddress& ip_address,
                                prefix_length_in_bits);
 }
 
+bool ParseCIDRBlock(const std::string& cidr_literal,
+                    IPAddress& ip_address,
+                    size_t& prefix_length_in_bits) {
+  // We expect CIDR notation to match one of these two templates:
+  //   <IPv4-literal> "/" <number of bits>
+  //   <IPv6-literal> "/" <number of bits>
+
+  std::vector<base::StringPiece> parts = base::SplitStringPiece(
+      cidr_literal, "/", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
+  if (parts.size() != 2)
+    return false;
+
+  // Parse the IP address.
+  if (!ip_address.AssignFromIPLiteral(parts[0]))
+    return false;
+
+  // Parse the prefix length.
+  int number_of_bits = -1;
+  if (!base::StringToInt(parts[1], &number_of_bits))
+    return false;
+
+  // Make sure the prefix length is in a valid range.
+  if (number_of_bits < 0 ||
+      number_of_bits > static_cast<int>(ip_address.size() * 8))
+    return false;
+
+  prefix_length_in_bits = static_cast<size_t>(number_of_bits);
+  return true;
+}
+
 unsigned CommonPrefixLength(const IPAddress& a1, const IPAddress& a2) {
   return CommonPrefixLength(a1.bytes(), a2.bytes());
 }