make SetReceiveBufferSize and SetSendBufferSize return net error codes (instead of bools)

net/http/http_proxy_client_socket.cc

Index: net/http/http_proxy_client_socket.cc
diff --git a/net/http/http_proxy_client_socket.cc b/net/http/http_proxy_client_socket.cc
index e2e46660dc2b52d42becb72b1b3e6c146f0afe3e..3d9eadd48353eaa61095581bcc22034e3e510e7f 100644
--- a/net/http/http_proxy_client_socket.cc
+++ b/net/http/http_proxy_client_socket.cc
@@ -237,11 +237,11 @@ int HttpProxyClientSocket::Write(IOBuffer* buf, int buf_len,
   return transport_->socket()->Write(buf, buf_len, callback);
 }
 
-bool HttpProxyClientSocket::SetReceiveBufferSize(int32 size) {
+int HttpProxyClientSocket::SetReceiveBufferSize(int32 size) {
   return transport_->socket()->SetReceiveBufferSize(size);
 }
 
-bool HttpProxyClientSocket::SetSendBufferSize(int32 size) {
+int HttpProxyClientSocket::SetSendBufferSize(int32 size) {
   return transport_->socket()->SetSendBufferSize(size);
 }