Add a message to the screen when depot tools have been updated....

update_depot_tools

 #!/usr/bin/env bash
 # Copyright (c) 2010 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")
 
 # Test git and git --version.
@@ skipping 20 matching lines @@
 
   GITV="${GITV#* version }"   # git svn --version has extra output to remove.
   GITV="${GITV% (svn*}"
   local GITD=( ${GITV//./ } ) # Split version number into decimals
   if ((GITD[0] < 1 || (GITD[0] == 1 && GITD[1] < 6) )); then
     echo "git version is ${GITV}, please update to a version later than 1.6"
     exit 1
   fi
 }
 
+# Get the current SVN revision.
+get_svn_revision() {
+  echo `svn info | awk '{ if ($1 == "Revision:") { print $2 }}'`
+}
 
 # 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 $base_dir
   test_git_svn
   # work around a git-svn --quiet bug
   OUTPUT=`git svn rebase -q -q`
   if [[ ! "$OUTPUT" == *Current.branch* ]]; then
     echo $OUTPUT
   fi
   cd - > /dev/null
 fi
 
 # We're on POSIX. 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.
+  BEFORE_REVISION=$(get_svn_revision)
   svn -q up "$base_dir"
+  AFTER_REVISION=$(get_svn_revision)
+  if [[ "$BEFORE_REVISION" != "$AFTER_REVISION" ]]; then

[M-A Ruel, 2011/03/14 00:42:48]

you could use?

if [ ! "$BEFORE_REVISION"=="$AFTER_REVISION" ]; then

but I'm no bash expert.

+    echo "Depot Tools has been updated to revision $AFTER_REVISION."
+  fi
 fi