Revert of Download the hermetic xcode toolchain on all bots that target mac.

scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Mac10_9.json

Index: scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Mac10_9.json
diff --git a/scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Mac10_9.json b/scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Mac10_9.json
index e3c0fb20942ebc6f6dbeb54cf11a661964f66999..ed106c91bbeddd68882cad1b11778436a1366743 100644
--- a/scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Mac10_9.json
+++ b/scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Mac10_9.json
@@ -200,7 +200,6 @@
     ],
     "cwd": "[BUILDER_CACHE]/mac_layout/src",
     "env": {
-      "FORCE_MAC_TOOLCHAIN": "1",
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json",
       "GYP_CHROMIUM_NO_ACTION": "1",
       "GYP_DEFINES": "clang=1 component=static_library gomadir='[CACHE]/cipd/goma' target_arch=x64 test_isolation_mode=prepare use_goma=1",
@@ -273,7 +272,6 @@
     ],
     "cwd": "[BUILDER_CACHE]/mac_layout/src",
     "env": {
-      "FORCE_MAC_TOOLCHAIN": "1",
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
     },
     "name": "generate_build_files"
@@ -290,7 +288,6 @@
       "/path/to/tmp/json"
     ],
     "env": {
-      "FORCE_MAC_TOOLCHAIN": "1",
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
     },
     "name": "clang_revision",
@@ -341,7 +338,6 @@
       "blink_tests"
     ],
     "env": {
-      "FORCE_MAC_TOOLCHAIN": "1",
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
     },
     "name": "compile",
@@ -416,7 +412,6 @@
     ],
     "cwd": "[BUILDER_CACHE]/mac_layout",
     "env": {
-      "FORCE_MAC_TOOLCHAIN": "1",
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
     },
     "name": "webkit_tests",
@@ -446,7 +441,6 @@
     ],
     "cwd": "[BUILDER_CACHE]/mac_layout",
     "env": {
-      "FORCE_MAC_TOOLCHAIN": "1",
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
     },
     "name": "archive_webkit_tests_results",