Use git svn rebase instead of git svn fetch & git svn merge

gclient

 #!/bin/sh
 # Copyright (c) 2009 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This script will try to sync the bootstrap directories and then defer control.
 
 base_dir=$(dirname "$0")
 
 # Update git checkouts prior the cygwin check, we don't want to use msysgit.
 if [ "X$DEPOT_TOOLS_UPDATE" != "X0" -a -e "$base_dir/.git" ]
 then
-  (cd "$base_dir"; git svn fetch -q; git merge trunk -q)
+  (cd "$base_dir"; git svn rebase -q -q)
 fi
 
 if [ "X$DEPOT_TOOLS_UPDATE" != "X0" -a -e "$base_dir/git-cl-repo/.git" ]
 then
   (cd "$base_dir/git-cl-repo"; git pull -q)
 fi
 
 if [ "X$DEPOT_TOOLS_UPDATE" != "X0" -a -e "$base_dir/git-try-repo/.git" ]
 then
   (cd "$base_dir/git-try-repo"; git pull -q)
 fi
 
 
 # Use the batch file as an entry point if on cygwin.
 if [ "${OSTYPE}" = "cygwin" -a "${TERM}" = "cygwin" ]; then
    ${base_dir}/gclient.bat "$@"
    exit
 fi
 
 
 # We're on POSIX (not cygwin). We can now safely look for svn checkout.
 if [ "X$DEPOT_TOOLS_UPDATE" != "X0" -a -e "$base_dir/.svn" ]
 then
   # Update the bootstrap directory to stay up-to-date with the latest
   # depot_tools.
   svn -q up "$base_dir"
 fi
 
 exec python "$base_dir/gclient.py" "$@"