Recipes: make cwd default to slave_build

scripts/slave/recipes/skia/skia.expected/Test-Mac10.8-Clang-MacMini4.1-GPU-GeForce320M-x86_64-Debug.json

Index: scripts/slave/recipes/skia/skia.expected/Test-Mac10.8-Clang-MacMini4.1-GPU-GeForce320M-x86_64-Debug.json
diff --git a/scripts/slave/recipes/skia/skia.expected/Test-Mac10.8-Clang-MacMini4.1-GPU-GeForce320M-x86_64-Debug.json b/scripts/slave/recipes/skia/skia.expected/Test-Mac10.8-Clang-MacMini4.1-GPU-GeForce320M-x86_64-Debug.json
index f438ecd5c4b9cba95cb11d0150fb74f72f08fdac..6a092f2e0094f82284d8f681db3301e6cf7c23e9 100644
--- a/scripts/slave/recipes/skia/skia.expected/Test-Mac10.8-Clang-MacMini4.1-GPU-GeForce320M-x86_64-Debug.json
+++ b/scripts/slave/recipes/skia/skia.expected/Test-Mac10.8-Clang-MacMini4.1-GPU-GeForce320M-x86_64-Debug.json
@@ -36,6 +36,7 @@
       "--spec",
       "cache_dir = None\nsolutions = [{'deps_file': 'DEPS', 'managed': True, 'name': 'skia', 'url': 'https://skia.googlesource.com/skia.git'}]"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "gclient setup"
   },
   {
@@ -53,6 +54,7 @@
       "--output-json",
       "/path/to/tmp/json"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "gclient sync",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -73,6 +75,7 @@
       "\nimport os\nimport sys\nwith open(sys.argv[1], 'w') as f:\n  f.write(os.path.join(os.path.expanduser('~'), 'src'))\n",
       "/path/to/tmp/"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "get CHROME_PATH",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",
@@ -106,6 +109,7 @@
       "[SLAVE_BUILD]/tmp",
       "511"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "makedirs tmp_dir",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",
@@ -128,6 +132,7 @@
       "[SLAVE_BUILD]/skia/SKP_VERSION",
       "/path/to/tmp/"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "Get expected SKP_VERSION"
   },
   {
@@ -138,6 +143,7 @@
       "[SLAVE_BUILD]/tmp/SKP_VERSION",
       "/path/to/tmp/"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "Get downloaded SKP_VERSION"
   },
   {
@@ -153,6 +159,7 @@
       "cat",
       "gs://chromium-skia-gm/skimage/input/TIMESTAMP_LAST_UPLOAD_COMPLETED"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "gsutil cat TIMESTAMP_LAST_UPLOAD_COMPLETED",
     "stdout": "/path/to/tmp/"
   },
@@ -164,6 +171,7 @@
       "[SLAVE_BUILD]/tmp/SKIMAGE_VERSION",
       "/path/to/tmp/"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "Get downloaded SKIMAGE_VERSION"
   },
   {
@@ -173,6 +181,7 @@
       "\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]/dm"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "rmtree dm",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",
@@ -192,6 +201,7 @@
       "[SLAVE_BUILD]/dm",
       "511"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "makedirs dm",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",
@@ -304,6 +314,7 @@
       "--nocpu",
       "--dummy-flags"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "env": {
       "CC": "/usr/bin/clang",
       "CXX": "/usr/bin/clang++"