Replace GetAllErrorCodesForUma calls with UMA_HISTOGRAM_SPARSE_SLOWLY.

net/base/net_errors.h

Index: net/base/net_errors.h
diff --git a/net/base/net_errors.h b/net/base/net_errors.h
index 64343f1ca10d0bf8477efc6a2497c1ec759072d6..a3b6040e853a9ec081ae8869fcbf30b4c6a86a09 100644
--- a/net/base/net_errors.h
+++ b/net/base/net_errors.h
@@ -48,15 +48,6 @@ NET_EXPORT bool IsClientCertificateError(int error);
 // Map system error code to Error.
 NET_EXPORT Error MapSystemError(logging::SystemErrorCode os_error);
 
-// Returns a list of all the possible net error codes (not counting OK). This
-// is intended for use with UMA histograms that are reporting the result of
-// an action that is represented as a net error code.
-//
-// Note that the error codes are all positive (since histograms expect positive
-// sample values). Also note that a guard bucket is created after any valid
-// error code that is not followed immediately by a valid error code.
-NET_EXPORT std::vector<int> GetAllErrorCodesForUma();
-
 // A convenient function to translate file error to net error code.
 NET_EXPORT Error FileErrorToNetError(base::File::Error file_error);