Add infra/build to DEPS

DEPS

 # This file contains dependencies for WebRTC.
 
 vars = {
   'chromium_git': 'https://chromium.googlesource.com',
   'chromium_revision': '22f522e10dd7a816ec45547fd35a6fa0356b3d21',
   'boringssl_git': 'https://boringssl.googlesource.com',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling swarming_client
   # and whatever else without interference from each other.
   'swarming_revision': '11e31afa5d330756ff87aa12064bb5d032896cb5',
@@ skipping 25 matching lines @@
 
 deps = {
   # TODO(kjellander): Move this to be Android-only once the libevent dependency
   # in base/third_party/libevent is solved.
   'src/base':
     Var('chromium_git') + '/chromium/src/base' + '@' + 'abda15d6dde1dae9da4db27426382d306bdb38f7',
   'src/build':
     Var('chromium_git') + '/chromium/src/build' + '@' + '6d17aaeb072c7e5f8645e7b2aca1669efd8eb81d',
   'src/buildtools':
     Var('chromium_git') + '/chromium/buildtools.git' + '@' + 'a7cc7a3e21a061975b33dcdcd81a9716ba614c3c',
+  'src/infra/build':
+    Var('chromium_git') + '/chromium/tools/build' + '@' + 'HEAD',
   'src/testing':
     Var('chromium_git') + '/chromium/src/testing' + '@' + '94e5046865181a121596d9564f13b132dfaa6973',
   'src/testing/gtest':
     Var('chromium_git') + '/external/github.com/google/googletest.git' + '@' + '6f8a66431cb592dad629028a50b3dd418a408c87',
   'src/testing/gmock':
     Var('chromium_git') + '/external/googlemock.git' + '@' + '0421b6f358139f02e102c9c332ce19a33faf75be', # from svn revision 566
   'src/third_party':
     Var('chromium_git') + '/chromium/src/third_party' + '@' + '071de702a424e71d0fe26eb8a445eaa1a8104154',
   'src/third_party/boringssl/src':
    Var('boringssl_git') + '/boringssl.git' + '@' +  Var('boringssl_revision'),
@@ skipping 471 matching lines @@
   },
 ]
 
 recursedeps = [
   # buildtools provides clang_format, libc++, and libc++abi.
   'src/buildtools',
   # android_tools manages the NDK.
   'src/third_party/android_tools',
 ]