Roll recipe dependencies (nontrivial).

scripts/slave/recipes/webrtc/standalone.expected/client_webrtc_linux64_release.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "\nimport sys, os\npath = sys.argv[1]\nmode = int(sys.argv[2])\nif not os.path.isdir(path):\n  if os.path.exists(path):\n    print \"%s exists but is not a dir\" % path\n    sys.exit(1)\n  os.makedirs(path, mode)\n",
       "[BUILDER_CACHE]/Linux64_Release",
       "511"
     ],
     "name": "makedirs checkout path",
@@ skipping 10 matching lines @@
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--spec",
       "cache_dir = '[GIT_CACHE]'\nsolutions = [{'deps_file': 'DEPS', 'managed': True, 'name': 'src', 'url': 'https://chromium.googlesource.com/external/webrtc'}, {'deps_file': 'DEPS', 'managed': True, 'name': 'webrtc-limited', 'url': 'https://chrome-internal.googlesource.com/chrome/deps/webrtc-limited'}]",
-      "--root",
+      "--patch_root",
       "src",
       "--revision_mapping_file",
       "{\"src\": \"got_revision\"}",
       "--git-cache-dir",
       "[GIT_CACHE]",
       "--output_json",
       "/path/to/tmp/json",
       "--revision",
       "src@12345",
       "--output_manifest"
@@ skipping 608 matching lines @@
     ],
     "cwd": "[BUILDER_CACHE]/Linux64_Release",
     "name": "webrtc_nonparallel_tests"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]