Use nacl_helper_bootstrap from native_client repository

DEPS

 vars = {
   # Use this googlecode_url variable only if there is an internal mirror for it.
   # If you do not know, use the full path while defining your new deps entry.
   "googlecode_url": "http://%s.googlecode.com/svn",
   "sourceforge_url": "http://%(repo)s.svn.sourceforge.net/svnroot/%(repo)s",
   "webkit_trunk": "http://svn.webkit.org/repository/webkit/trunk",
   "nacl_trunk": "http://src.chromium.org/native_client/trunk",
   "webkit_revision": "101876",
   "chromium_git": "http://git.chromium.org/git",
   "swig_revision": "69281",
@@ skipping 15 matching lines @@
       "56d82b794c3523a43068a5b69236277a96de04c5",
   "nacl_toolchain_win_x86_hash":
       "c5af5469b2252f3d5bb9ce4a7758b4537e9c5b16",
   "nacl_toolchain_win_x86_newlib_hash":
       "40d182ac25fe6623cfbe5772623c15c663a42c93",
   "nacl_toolchain_revision": "7332",
 
   "libjingle_revision": "99",
   "libphonenumber_revision": "407",
   "libvpx_revision": "109236",
+  "lss_revision": "9",
   "ffmpeg_revision": "112050",
   "sfntly_revision": "111",
   "skia_revision": "2785",
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and V8 without interference from each other.
   "v8_revision": "10163",
   "webrtc_revision": "1027",
   "jsoncpp_revision": "246",
 }
@@ skipping 349 matching lines @@
     "src/chrome/tools/test/reference_build/chrome_linux":
       "/trunk/deps/reference_builds/chrome_linux@89574",
 
     "src/third_party/xdg-utils":
       "/trunk/deps/third_party/xdg-utils@93299",
 
     "src/third_party/swig/linux":
       "/trunk/deps/third_party/swig/linux@" + Var("swig_revision"),
 
     "src/third_party/lss":
-      (Var("googlecode_url") % "linux-syscall-support") + "/trunk/lss@8",
+      ((Var("googlecode_url") % "linux-syscall-support") + "/trunk/lss@" +
+       Var("lss_revision")),
 
     "src/third_party/openssl":
       "/trunk/deps/third_party/openssl@105093",
 
     "src/third_party/WebKit/Tools/gdb":
       Var("webkit_trunk") + "/Tools/gdb@" + Var("webkit_revision"),
   },
 }
 
 
@@ skipping 59 matching lines @@
     # which takes ~20s, but clang speeds up builds by more than 20s.
     "pattern": ".",
     "action": ["python", "src/tools/clang/scripts/update.py", "--mac-only"],
   },
   {
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     "pattern": ".",
     "action": ["python", "src/build/gyp_chromium"],
   },
 ]