Recipes: make cwd default to slave_build

scripts/slave/recipes/chromium.expected/dynamic_script_test_with_args.json

Index: scripts/slave/recipes/chromium.expected/dynamic_script_test_with_args.json
diff --git a/scripts/slave/recipes/chromium.expected/dynamic_script_test_with_args.json b/scripts/slave/recipes/chromium.expected/dynamic_script_test_with_args.json
index edfccca07132f8930cc4ef8421ac0c89e24016f1..c78d2ff9eb412d5ddcbd164e7ed2258228c122ec 100644
--- a/scripts/slave/recipes/chromium.expected/dynamic_script_test_with_args.json
+++ b/scripts/slave/recipes/chromium.expected/dynamic_script_test_with_args.json
@@ -21,6 +21,7 @@
       "--revision",
       "src@HEAD"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "bot_update",
     "~followup_annotations": [
       "@@@STEP_TEXT@Some step text@@@",
@@ -67,6 +68,7 @@
       "[SLAVE_BUILD]/src/tools/swarming_client/swarming.py",
       "--version"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "swarming.py --version",
     "stdout": "/path/to/tmp/",
     "~followup_annotations": [
@@ -80,6 +82,7 @@
       "[DEPOT_TOOLS]/gclient.py",
       "runhooks"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "env": {
       "GYP_DEFINES": "component=static_library gomadir='[BUILD]/goma' target_arch=x64 test_isolation_mode=prepare use_goma=1"
     },
@@ -93,6 +96,7 @@
       "[SLAVE_BUILD]/src/testing/buildbot/chromium.linux.json",
       "/path/to/tmp/json"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "read test spec",
     "~followup_annotations": [
       "@@@STEP_TEXT@path: [SLAVE_BUILD]/src/testing/buildbot/chromium.linux.json@@@",
@@ -128,6 +132,7 @@
       "--properties",
       "{\"buildername\": \"Linux Tests\", \"buildnumber\": 571, \"mastername\": \"chromium.linux\", \"slavename\": \"TestSlavename\", \"target_platform\": \"linux\"}"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "get compile targets for scripts",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{}@@@",
@@ -140,6 +145,7 @@
       "-u",
       "[BUILD]/scripts/slave/cleanup_temp.py"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "cleanup_temp"
   },
   {
@@ -149,6 +155,7 @@
       "\nimport os, sys\nfrom common import chromium_utils\n\nif os.path.exists(sys.argv[1]):\n  chromium_utils.RemoveDirectory(sys.argv[1])\n",
       "[SLAVE_BUILD]/src/out/Release"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "rmtree build directory",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",
@@ -176,6 +183,7 @@
       "--build-properties",
       "{\"blamelist\": [\"cool_dev1337@chromium.org\", \"hax@chromium.org\"], \"buildername\": \"Linux Tests\", \"buildnumber\": 571, \"mastername\": \"chromium.linux\", \"parent_buildername\": \"Linux Builder\", \"recipe\": \"chromium\", \"slavename\": \"TestSlavename\", \"workdir\": \"/path/to/workdir/TestSlavename\"}"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "extract build"
   },
   {
@@ -195,6 +203,7 @@
       "--output",
       "/path/to/tmp/json"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "media_perftests",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",