Recipes: make cwd default to slave_build

scripts/slave/recipes/webrtc/chromium.expected/chromium_webrtc_fyi_Android_GN.json

Index: scripts/slave/recipes/webrtc/chromium.expected/chromium_webrtc_fyi_Android_GN.json
diff --git a/scripts/slave/recipes/webrtc/chromium.expected/chromium_webrtc_fyi_Android_GN.json b/scripts/slave/recipes/webrtc/chromium.expected/chromium_webrtc_fyi_Android_GN.json
index 5e4981fc9f1db3c76e967d2fe9cf5dc925c7039d..344da3fe79326343b3ae1e47e26f057b040e9d8d 100644
--- a/scripts/slave/recipes/webrtc/chromium.expected/chromium_webrtc_fyi_Android_GN.json
+++ b/scripts/slave/recipes/webrtc/chromium.expected/chromium_webrtc_fyi_Android_GN.json
@@ -25,6 +25,7 @@
       "--revision",
       "src/third_party/webrtc@HEAD"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "bot_update",
     "~followup_annotations": [
       "@@@STEP_TEXT@Some step text@@@",
@@ -79,6 +80,7 @@
       "RECIPE_MODULE[webrtc]/resources/cleanup_files.py",
       "[SLAVE_BUILD]/src/out"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "clean test output files"
   },
   {
@@ -91,6 +93,7 @@
       "[SLAVE_BUILD]/src/out/build_product.zip",
       "[SLAVE_BUILD]/src"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "clean local files",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",
@@ -115,6 +118,7 @@
       "[DEPOT_TOOLS]/gclient.py",
       "runhooks"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "env": {
       "GYP_CHROMIUM_NO_ACTION": "1",
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
@@ -131,6 +135,7 @@
       "//out/Release",
       "--args=symbol_level=1 is_debug=false target_os=\"android\" target_cpu=\"arm\" use_goma=true goma_dir=\"[BUILD]/goma\""
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "gn"
   },
   {
@@ -151,6 +156,7 @@
       "--",
       "chrome_shell_apk"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "env": {
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s"
     },