Include version information in Linux chrome.

chrome/tools/build/linux/version.sh

 #!/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.
 
 # TODO(mmoss) This is (mostly) just a conversion to sh syntax of
 # tools/build/win/version.bat. Rewrite both as common python.
 
 TMPL="$1"
@@ skipping 17 matching lines @@
 if [ -z "$LASTCHANGE" ]; then
   # Maybe it's a git client
   LASTCHANGE=$(git-svn info 2>/dev/null | grep "Revision:" | cut -d" " -f2-)
 fi
 
 OFFICIAL_BUILD="false"
 if [ "$CHROME_BUILD_TYPE" = "_official" ]; then
   OFFICIAL_BUILD="true"
 fi
 
+# Write to a temp file and only overwrite the target if it changes, to avoid
+# unnecessary compiles due to timestamp changes.
+TMPFILE=$(mktemp -q -t chromiumver-XXXX)
+if [ $? -ne 0 ]; then
+  # Oops, just use the target file and suffer possibly unnecessary compile.
+  TMPFILE="$OUTFILE"
+fi
+
 # TODO(mmoss) Make sure no sed special chars in substitutions.
 sed -e "s/@MAJOR@/$MAJOR/" \
     -e "s/@MINOR@/$MINOR/" \
     -e "s/@BUILD@/$BUILD/" \
     -e "s/@PATCH@/$PATCH/" \
     -e "s/@COMPANY_FULLNAME@/$COMPANY_FULLNAME/" \
     -e "s/@COMPANY_SHORTNAME@/$COMPANY_SHORTNAME/" \
     -e "s/@PRODUCT_FULLNAME@/$PRODUCT_FULLNAME/" \
     -e "s/@PRODUCT_SHORTNAME@/$PRODUCT_SHORTNAME/" \
     -e "s/@PRODUCT_EXE@/$PRODUCT_EXE/" \
     -e "s/@COPYRIGHT@/$COPYRIGHT/" \
     -e "s/@OFFICIAL_BUILD@/$OFFICIAL_BUILD/" \
-    -e "s/@LASTCHANGE@/$LASTCHANGE/" "$TMPL" > "$OUTFILE"
+    -e "s/@LASTCHANGE@/$LASTCHANGE/" "$TMPL" > "$TMPFILE"
+
+diff -q "$TMPFILE" "$OUTFILE" >/dev/null 2>&1
+if [ $? -ne 0 ]; then
+  mv -f "$TMPFILE" "$OUTFILE"
+else
+  rm "$TMPFILE"
+fi