Add metrics for DHCP WPAD feature.

net/base/net_errors.cc

Index: net/base/net_errors.cc
diff --git a/net/base/net_errors.cc b/net/base/net_errors.cc
index 6c0e09c7f13dd06b5bc63cfd674f28bd95368523..4aab9cbc7691fdd8794f8ad085a273e23f2bff04 100644
--- a/net/base/net_errors.cc
+++ b/net/base/net_errors.cc
@@ -26,4 +26,12 @@ const char* ErrorToString(int error) {
   }
 }
 
+std::vector<int> GetAllErrorCodesForUma() {
+  std::vector<int> all_error_codes;
+#define NET_ERROR(label, value) all_error_codes.push_back(-(value));

[jar (doing other things), 2011/05/19 23:25:38]

Although this was copied....  it might be better to push two cutoffs per error
code, so that IF there is an intermediate value, it is not accidentally lumped
with the previous bucket.  Note that the underlying HISTOGRAM will get rid of
dups, so you don't need to worry about that eventuality.  The code might then
look like:

#define NET_ERROR(laber, value) all_error_codes.push_back(-(value)) ; \
all_error_codes.push_back(1 - (value));

IF you do make this change, you may want to rename any existing users of this
list so that they don't conflate the existing uploads (though you can always
split them out by version).

+#include "net/base/net_error_list.h"
+#undef NET_ERROR
+  return all_error_codes;
+}
+
 }  // namespace net