Use find_depot_tools.py and vs_toolchain.py from chromium/src/build/

tools/Makefile

 # Copyright (c) 2012 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 ##############################################################################
 # Helper script for NaCl toolchain development workflow.
 #
 # Buildbots:
 # - Sync needed sources at pinned revision and build newlib-based toolchain:
 #     make buildbot-build-with-newlib TOOLCHAINLOC=<where-to-install-the-toolchain>
@@ skipping 93 matching lines @@
 # use, obviously - and this is not always the case: for example they are not
 # available on MacOS, on 64bit linux you generally can find 64bit versions of
 # them, but not 32bit versions, etc).
 SRCDIR = ../../../third_party
 
 ifeq ($(PLATFORM), win)
   # Ugh, Cygwin and spaces in paths don't work well.
   # I'm explicitly coding the path.
   BUILDPATH = $(DESTDIR)$(PREFIX)/bin:/usr/local/bin:/usr/bin:/bin
   SCONS ?= scons.bat
-  GIT ?= $(shell python ../build/find_depot_tools.py)/git.bat
+  GIT ?= $(shell python ../../build/find_depot_tools.py)/git.bat
   REVISION ?= $(shell $(GIT) rev-parse HEAD | tr -d $$"\r")
   PREFIX_NATIVE = $(shell cygpath -m $(PREFIX))
   CREATE_REDIRECTORS = ./create_redirectors_cygwin.sh
 else
   BUILDPATH = $(DESTDIR)$(PREFIX)/bin:$(PATH)
   SCONS ?= scons
   GIT ?= git
   REVISION ?= $(shell git rev-parse HEAD)
   PREFIX_NATIVE = $(DESTDIR)$(PREFIX)
   CREATE_REDIRECTORS = ./create_redirectors.sh
@@ skipping 919 matching lines @@
 
 
 ##################################################################
 # Remove the BUILD directory.
 # Library builds are maintained by scons.
 ##################################################################
 
 .PHONY: clean
 clean:
         rm -rf BUILD/*