Fix instability in SSL client/server sockets

net/socket/ssl_client_socket_nss.cc

Index: net/socket/ssl_client_socket_nss.cc
diff --git a/net/socket/ssl_client_socket_nss.cc b/net/socket/ssl_client_socket_nss.cc
index e827f398db65eb56a946e5c1ed286f455ccccb12..e1a654577e5c5ecb31ae55685bdf34b52fbfda33 100644
--- a/net/socket/ssl_client_socket_nss.cc
+++ b/net/socket/ssl_client_socket_nss.cc
@@ -1734,15 +1734,26 @@ void SSLClientSocketNSS::UncorkAfterTimeout() {
   } while (nsent > 0);
 }
 
-// Do network I/O between the given buffer and the given socket.
-// Return true if some I/O performed, false otherwise (error or ERR_IO_PENDING)
+// Do as much as possible network I/O between the buffer and the
+// transport socket. Return true if some I/O performed, false
+// otherwise (error or ERR_IO_PENDING).
 bool SSLClientSocketNSS::DoTransportIO() {
   EnterFunction("");
   bool network_moved = false;
   if (nss_bufs_ != NULL) {
-    int nsent = BufferSend();
-    int nreceived = BufferRecv();
-    network_moved = (nsent > 0 || nreceived >= 0);
+    int rv;
+    // Read and write as much data as we can. Loops are neccessary
+    // because Read() and Write() may return synchronously.
+    do {
+      rv = BufferSend();
+      if (rv > 0)
+        network_moved = true;
+    } while (rv > 0);
+    do {
+      rv = BufferRecv();
+      if (rv >= 0)
+        network_moved = true;
+    } while (rv > 0);
   }
   LeaveFunction(network_moved);
   return network_moved;