Add an opt-out header for HTTP throttling. Never throttle for localhost.

net/base/net_util.h

Index: net/base/net_util.h
diff --git a/net/base/net_util.h b/net/base/net_util.h
index 9e30d2b052948701a24fda85c21908ef503d271a..0ed082906a9b074cc64f0b5995101e1a8c6217d7 100644
--- a/net/base/net_util.h
+++ b/net/base/net_util.h
@@ -427,6 +427,15 @@ const uint16* GetPortFieldFromSockaddr(const struct sockaddr* address,
 int GetPortFromSockaddr(const struct sockaddr* address,
                         socklen_t address_len);
 
+// Returns true if |host| is one of the names (e.g. "localhost") or IP
+// addresses (IPv4 127.0.0.0/8 or IPv6 ::1) that indicate a loopback.
+//
+// Note that this function does not check for IP addresses other than
+// the above that have been mapped back to the local machine, i.e.

[wtc, 2011/03/25 19:06:24]

Nit: "mapped back to the local machine" is a little confusing.
Do you mean IP addresses of the local machine?  Or do you
mean /etc/hosts can map an IP address to 127.0.0.1?

[Jói, 2011/03/25 21:26:51]

Yes, I mean via /etc/hosts or by the host admin making other IPv6 addresses into
loopback addresses.  I've simplified the comment to simply state:


// Note that this function does not check for IP addresses other than
// the above, although other IP addresses may point to the local
// machine.

+// it only checks for IP addresses that by definition are loopback
+// addresses.
+bool IsLocalhost(const std::string& host);
+
 // struct that is used by GetNetworkList() to represent a network
 // interface.
 struct NetworkInterface {