Recipes: make cwd default to slave_build

scripts/slave/recipes/chromium_gn.expected/full_client_v8_V8_Linux_GN.json

Index: scripts/slave/recipes/chromium_gn.expected/full_client_v8_V8_Linux_GN.json
diff --git a/scripts/slave/recipes/chromium_gn.expected/full_client_v8_V8_Linux_GN.json b/scripts/slave/recipes/chromium_gn.expected/full_client_v8_V8_Linux_GN.json
index b779a3c45dbc065ac1f1e552c33e77d643c07f26..7681ead89830d84773299a8b2722f48038a79986 100644
--- a/scripts/slave/recipes/chromium_gn.expected/full_client_v8_V8_Linux_GN.json
+++ b/scripts/slave/recipes/chromium_gn.expected/full_client_v8_V8_Linux_GN.json
@@ -24,6 +24,7 @@
       "src/v8@HEAD",
       "--force"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "bot_update",
     "~followup_annotations": [
       "@@@STEP_TEXT@Some step text@@@",
@@ -66,6 +67,7 @@
       "[DEPOT_TOOLS]/gclient.py",
       "runhooks"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "env": {
       "GYP_CHROMIUM_NO_ACTION": "1"
     },
@@ -88,6 +90,7 @@
       "[BUILD]/goma",
       "//out/Release"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "Generate build files"
   },
   {
@@ -98,6 +101,7 @@
       "[SLAVE_BUILD]/src/testing/buildbot/client.v8.json",
       "/path/to/tmp/json"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "read test spec",
     "~followup_annotations": [
       "@@@STEP_TEXT@path: [SLAVE_BUILD]/src/testing/buildbot/client.v8.json@@@",
@@ -130,6 +134,7 @@
       "base_unittests",
       "all"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "compile"
   },
   {
@@ -141,6 +146,7 @@
       "check",
       "//out/Release"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "gn check"
   }
 ]