Add reprioritization to socket pools.

net/socket/client_socket_pool.h

Index: net/socket/client_socket_pool.h
diff --git a/net/socket/client_socket_pool.h b/net/socket/client_socket_pool.h
index 15dbe5f02d6e09d6e503c6dccb4eab0a268e4949..94c36391cbcd40da1e71826cfe24b788aca58f96 100644
--- a/net/socket/client_socket_pool.h
+++ b/net/socket/client_socket_pool.h
@@ -124,6 +124,16 @@ class NET_EXPORT ClientSocketPool : public LowerLayeredPool {
                               int num_sockets,
                               const NetLogWithSource& net_log) = 0;
 
+  // Called to change the priority of a RequestSocket call that returned
+  // ERR_IO_PENDING and has not yet asynchronously completed.  The same handle
+  // parameter must be passed to this method as was passed to the
+  // RequestSocket call being modified.
+  // This function is a no-op if |priority| is the same as the current
+  // request priority.
+  virtual void SetPriority(const std::string& group_name,
+                           ClientSocketHandle* handle,
+                           RequestPriority priority) = 0;
+
   // Called to cancel a RequestSocket call that returned ERR_IO_PENDING.  The
   // same handle parameter must be passed to this method as was passed to the
   // RequestSocket call being cancelled.  The associated CompletionCallback is