Extend net/base/parse_number.h for parsing of negative numbers, and determining if there was overflo

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 b805317eef3675ea0dafe63353bef32bb199c8aa..e17f0e3e88c0bda67d696c57951c932fb3c4a882 100644
--- a/net/base/ip_address.cc
+++ b/net/base/ip_address.cc
@@ -180,16 +180,15 @@ bool ParseCIDRBlock(const std::string& cidr_literal,
     return false;
 
   // Parse the prefix length.
-  int number_of_bits = -1;
-  if (!ParseNonNegativeDecimalInt(parts[1], &number_of_bits))
+  size_t number_of_bits;
+  if (!ParseUnsignedIntegerBase10(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))
+  if (number_of_bits > ip_address->size() * 8)
     return false;
 
-  *prefix_length_in_bits = static_cast<size_t>(number_of_bits);
+  *prefix_length_in_bits = number_of_bits;
   return true;
 }