Recipes: make cwd default to slave_build

scripts/slave/recipes/dart/dartium_build.expected/basic_mac_64_MirrorFalse.json

Index: scripts/slave/recipes/dart/dartium_build.expected/basic_mac_64_MirrorFalse.json
diff --git a/scripts/slave/recipes/dart/dartium_build.expected/basic_mac_64_MirrorFalse.json b/scripts/slave/recipes/dart/dartium_build.expected/basic_mac_64_MirrorFalse.json
index 0299e579e107c1635911cd9fb17a815833e0830d..f6cb4f16a948468690a517908641a6f2fcbe9cb0 100644
--- a/scripts/slave/recipes/dart/dartium_build.expected/basic_mac_64_MirrorFalse.json
+++ b/scripts/slave/recipes/dart/dartium_build.expected/basic_mac_64_MirrorFalse.json
@@ -8,6 +8,7 @@
       "--spec",
       "cache_dir = None\nsolutions = [{'deps_file': 'DEPS', 'managed': True, 'name': 'dartium.deps', 'url': 'https://dart.googlecode.com/svn/branches/bleeding_edge/deps/dartium.deps'}]"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "gclient setup"
   },
   {
@@ -25,6 +26,7 @@
       "--output-json",
       "/path/to/tmp/json"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "gclient sync",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -68,6 +70,7 @@
       "[DEPOT_TOOLS]/gclient.py",
       "runhooks"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "env": {
       "GYP_DEFINES": "clang=1 component=static_library gomadir='[BUILD]/goma' linux_strip_binary=1 target_arch=x64 use_goma=1",
       "GYP_GENERATORS": "ninja"
@@ -93,6 +96,7 @@
       "All",
       "chromium_builder_tests"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "compile"
   },
   {
@@ -102,6 +106,7 @@
       "[SLAVE_BUILD]/src/dart/tools/dartium/multivm_archive.py",
       "12345"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "archive_build"
   }
 ]