webrtc: prepare for running under remote_run

scripts/slave/recipes/webrtc/ios_api_framework.expected/trybot_build.json

 [
   {
     "cmd": [
       "RECIPE_PACKAGE_REPO[build]/scripts/slave/ios/host_info.py",
       "--json-file",
       "/path/to/tmp/json"
     ],
     "name": "host and tools info",
     "~followup_annotations": [
       "@@@STEP_TEXT@<br />OS X 1.2.3, Xcode 6.7.8 (5D342509a)@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"Mac OS X Version\": \"1.2.3\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"Xcode Build Version\": \"5D342509a\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"Xcode SDKs\": [@@@",
       "@@@STEP_LOG_LINE@json.output@    \"fake sdk 1.0\", @@@",
       "@@@STEP_LOG_LINE@json.output@    \"fake sdk 1.1\", @@@",
       "@@@STEP_LOG_LINE@json.output@    \"fake sdk 2.0\"@@@",
       "@@@STEP_LOG_LINE@json.output@  ], @@@",
       "@@@STEP_LOG_LINE@json.output@  \"Xcode Version\": \"6.7.8\"@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@"
     ]
   },
   {
     "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]/ios_api_framework",
+      "511"
+    ],
+    "name": "makedirs checkout path",
+    "~followup_annotations": [
+      "@@@STEP_LOG_LINE@python.inline@@@@",
+      "@@@STEP_LOG_LINE@python.inline@import sys, os@@@",
+      "@@@STEP_LOG_LINE@python.inline@path = sys.argv[1]@@@",
+      "@@@STEP_LOG_LINE@python.inline@mode = int(sys.argv[2])@@@",
+      "@@@STEP_LOG_LINE@python.inline@if not os.path.isdir(path):@@@",
+      "@@@STEP_LOG_LINE@python.inline@  if os.path.exists(path):@@@",
+      "@@@STEP_LOG_LINE@python.inline@    print \"%s exists but is not a dir\" % path@@@",
+      "@@@STEP_LOG_LINE@python.inline@    sys.exit(1)@@@",
+      "@@@STEP_LOG_LINE@python.inline@  os.makedirs(path, mode)@@@",
+      "@@@STEP_LOG_END@python.inline@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--master",
       "tryserver.webrtc",
       "--builder",
       "ios_api_framework",
       "--slave",
       "TestSlavename",
       "--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'}]\ntarget_os = ['ios', 'mac']",
       "--root",
       "src",
       "--revision_mapping_file",
       "{\"src\": \"got_revision\"}",
       "--git-cache-dir",
       "[GIT_CACHE]",
       "--issue",
       "12853011",
       "--patchset",
       "1",
       "--rietveld_server",
       "https://codereview.chromium.org",
       "--output_json",
       "/path/to/tmp/json",
       "--revision",
       "src@HEAD",
       "--output_manifest"
     ],
+    "cwd": "[BUILDER_CACHE]/ios_api_framework",
     "env": {
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "bot_update",
     "~followup_annotations": [
       "@@@STEP_TEXT@Some step text@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"did_run\": true, @@@",
       "@@@STEP_LOG_LINE@json.output@  \"fixed_revisions\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"src\": \"HEAD\"@@@",
@@ skipping 18 matching lines @@
       "@@@SET_BUILD_PROPERTY@got_revision_cp@\"refs/heads/master@{#170242}\"@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
       "runhooks"
     ],
-    "cwd": "[SLAVE_BUILD]/src",
+    "cwd": "[BUILDER_CACHE]/ios_api_framework/src",
     "env": {
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "gclient runhooks"
   },
   {
     "cmd": [
-      "[SLAVE_BUILD]/src/webrtc/build/ios/build_ios_libs.sh",
+      "[BUILDER_CACHE]/ios_api_framework/src/webrtc/build/ios/build_ios_libs.sh",
       "-r",
       "170242"
     ],
-    "cwd": "[SLAVE_BUILD]/src",
+    "cwd": "[BUILDER_CACHE]/ios_api_framework/src",
     "name": "build"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]