Recipes: make cwd default to slave_build

scripts/slave/recipes/skia/skia.expected/Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Debug-Trybot.json

Index: scripts/slave/recipes/skia/skia.expected/Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Debug-Trybot.json
diff --git a/scripts/slave/recipes/skia/skia.expected/Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Debug-Trybot.json b/scripts/slave/recipes/skia/skia.expected/Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Debug-Trybot.json
index 93c89ecbac8e4c863e785303f09e4cc5e385d7df..e50cf960d6256a552ed21d9023ac23df9886c3ea 100644
--- a/scripts/slave/recipes/skia/skia.expected/Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Debug-Trybot.json
+++ b/scripts/slave/recipes/skia/skia.expected/Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Debug-Trybot.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"
   },
   {
@@ -46,6 +47,7 @@
       ".",
       "[DEPOT_TOOLS]/gclient"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "gclient revert"
   },
   {
@@ -63,6 +65,7 @@
       "--output-json",
       "/path/to/tmp/json"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "gclient sync",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -91,6 +94,7 @@
       "https://codereview.chromium.org",
       "--no-auth"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "apply_issue",
     "~followup_annotations": [
       "@@@STEP_LINK@Applied issue 500@https://codereview.chromium.org/500@@@"
@@ -103,6 +107,7 @@
       "\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@@@@",
@@ -134,6 +139,7 @@
       "[SLAVE_BUILD]/tmp",
       "511"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "makedirs tmp_dir",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",
@@ -156,6 +162,7 @@
       "[SLAVE_BUILD]/skia/SKP_VERSION",
       "/path/to/tmp/"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "Get expected SKP_VERSION"
   },
   {
@@ -166,6 +173,7 @@
       "[SLAVE_BUILD]/tmp/SKP_VERSION",
       "/path/to/tmp/"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "Get downloaded SKP_VERSION"
   },
   {
@@ -181,6 +189,7 @@
       "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/"
   },
@@ -192,6 +201,7 @@
       "[SLAVE_BUILD]/tmp/SKIMAGE_VERSION",
       "/path/to/tmp/"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "Get downloaded SKIMAGE_VERSION"
   },
   {
@@ -201,6 +211,7 @@
       "\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@@@@",
@@ -220,6 +231,7 @@
       "[SLAVE_BUILD]/dm",
       "511"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "makedirs dm",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",
@@ -332,6 +344,7 @@
       "--nogpu",
       "--dummy-flags"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "dm"
   },
   {