depot_tools: Add .js to git-gs.

BUG=None
TEST=None

Signed-off-by: Thiago Farina <tfarina@chromium.org>

Review URL: http://codereview.chromium.org/2847075

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@53938 0039d316-1c4b-4281-b951-d872f2087c98

git-gs

@@ -5,5 +5,5 @@
 git grep -n -e "$@" -- "*.h" "*.hpp" "*.cpp" "*.c" "*.cc" "*.cpp" "*.inl"\
    "*.grd" "*.idl" "*.m" "*.mm" "*.py" "*.sh" "*.cfg"\
    "*SConscript" "SConscript*" "*.scons" "*.vcproj" "*.vsprops" "*.make"\
-   "*.gyp" "*.gypi"
+   "*.gyp" "*.gypi" "*.js"