Adding *.pm and *.pl files to the list searched by 'git gs'.

BUG=155016

Review URL: https://chromiumcodereview.appspot.com/11028112

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@161109 0039d316-1c4b-4281-b951-d872f2087c98

git-gs

@@ -5,4 +5,4 @@
 git grep -n -e "$@" -- "*.h" "*.hpp" "*.cpp" "*.c" "*.cc" "*.cpp" "*.inl"\
    "*.grd" "*.idl" "*.m" "*.mm" "*.py" "*.sh" "*.cfg" "*.tac" "*.go"\
    "*SConscript" "SConscript*" "*.scons" "*.vcproj" "*.vsprops" "*.make"\
-   "*.gyp" "*.gypi" "*.isolate" "*.js" "*.html" "*.css" "*.ebuild"
+   "*.gyp" "*.gypi" "*.isolate" "*.js" "*.html" "*.css" "*.ebuild" "*.pl" "*.pm"