Make dart recipes explicitly set GIT_MODE

scripts/slave/recipes/dart/dartium_build.expected/basic_linux_64_MirrorTrue.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
       "config",
       "--spec",
-      "cache_dir = '[GIT_CACHE]'\nsolutions = [{'custom_vars': {'dartium_base': 'svn://svn-mirror.golo.chromium.org', 'googlecode_url': 'svn://svn-mirror.golo.chromium.org/%s', 'nacl_trunk': 'svn://svn-mirror.golo.chromium.org/native_client/trunk', 'sourceforge_url': 'svn://svn-mirror.golo.chromium.org/%(repo)s', 'webkit_trunk': 'svn://svn-mirror.golo.chromium.org/blink/trunk'}, 'deps_file': 'DEPS', 'managed': True, 'name': 'dartium.deps', 'url': 'svn://svn-mirror.golo.chromium.org/dart/branches/bleeding_edge/deps/dartium.deps'}]"
+      "cache_dir = '[GIT_CACHE]'\nsolutions = [{'custom_vars': {'dartium_base': 'svn://svn-mirror.golo.chromium.org', 'googlecode_url': 'svn://svn-mirror.golo.chromium.org/%s', 'nacl_trunk': 'svn://svn-mirror.golo.chromium.org/native_client/trunk', 'sourceforge_url': 'svn://svn-mirror.golo.chromium.org/%(repo)s', 'webkit_trunk': 'https://chromium.googlesource.com/chromium/blink.git'}, 'deps_file': '.DEPS.git', 'managed': True, 'name': 'dartium.deps', 'url': 'svn://svn-mirror.golo.chromium.org/dart/branches/bleeding_edge/deps/dartium.deps'}]"
     ],
     "env": {
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "gclient setup"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
       "sync",
+      "--verbose",
+      "--with_branch_heads",
       "--nohooks",
+      "-j8",
+      "--reset",
       "--force",
-      "--verbose",
+      "--upstream",
+      "--no-nag-max",
       "--delete_unversioned_trees",
       "--revision",
       "dartium.deps@12345",
       "--output-json",
       "/path/to/tmp/json"
     ],
     "env": {
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "gclient sync",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"solutions\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"dartium.deps/\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": 10382@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"bea6ebce06cbfe65b527a51e99dd7f7a8110bc00\"@@@",
       "@@@STEP_LOG_LINE@json.output@    }, @@@",
       "@@@STEP_LOG_LINE@json.output@    \"src/buildtools/\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": 182578@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"f0319a328b2809876916353cb994259692140934\"@@@",
       "@@@STEP_LOG_LINE@json.output@    }, @@@",
       "@@@STEP_LOG_LINE@json.output@    \"src/dart/\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": 58622@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"1611b2bececca8bb2d75288f75ab5f1e1b44a482\"@@@",
       "@@@STEP_LOG_LINE@json.output@    }, @@@",
       "@@@STEP_LOG_LINE@json.output@    \"src/native_client/\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": 274981@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"d998e125e8253980d76e269b7982aeeefc1b9b50\"@@@",
       "@@@STEP_LOG_LINE@json.output@    }, @@@",
       "@@@STEP_LOG_LINE@json.output@    \"src/third_party/angle/\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": 297276@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"fac9503c46405f77757b9a728eb85b8d7bc6080c\"@@@",
       "@@@STEP_LOG_LINE@json.output@    }, @@@",
       "@@@STEP_LOG_LINE@json.output@    \"src/third_party/webrtc/\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": 120644@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"0f90628433546e61d9268596da93418c623137f4\"@@@",
       "@@@STEP_LOG_LINE@json.output@    }, @@@",
       "@@@STEP_LOG_LINE@json.output@    \"src/tools/swarming_client/\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": 276089@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"a0ee5d99f1d4b38ddaa4c759c837980b63b99566\"@@@",
       "@@@STEP_LOG_LINE@json.output@    }, @@@",
       "@@@STEP_LOG_LINE@json.output@    \"src/v8/\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": 43426@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"801ada225ddc271c132c3a35f03975671d43e399\"@@@",
       "@@@STEP_LOG_LINE@json.output@    }@@@",
       "@@@STEP_LOG_LINE@json.output@  }@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@",
-      "@@@SET_BUILD_PROPERTY@got_nacl_revision@274981@@@",
-      "@@@SET_BUILD_PROPERTY@got_swarming_client_revision@276089@@@",
-      "@@@SET_BUILD_PROPERTY@got_webrtc_revision@120644@@@",
-      "@@@SET_BUILD_PROPERTY@got_revision@58622@@@",
-      "@@@SET_BUILD_PROPERTY@got_angle_revision@297276@@@",
-      "@@@SET_BUILD_PROPERTY@got_v8_revision@43426@@@",
-      "@@@SET_BUILD_PROPERTY@got_buildtools_revision@182578@@@"
+      "@@@SET_BUILD_PROPERTY@got_nacl_revision@\"d998e125e8253980d76e269b7982aeeefc1b9b50\"@@@",
+      "@@@SET_BUILD_PROPERTY@got_swarming_client_revision@\"a0ee5d99f1d4b38ddaa4c759c837980b63b99566\"@@@",
+      "@@@SET_BUILD_PROPERTY@got_webrtc_revision@\"0f90628433546e61d9268596da93418c623137f4\"@@@",
+      "@@@SET_BUILD_PROPERTY@got_revision@\"1611b2bececca8bb2d75288f75ab5f1e1b44a482\"@@@",
+      "@@@SET_BUILD_PROPERTY@got_angle_revision@\"fac9503c46405f77757b9a728eb85b8d7bc6080c\"@@@",
+      "@@@SET_BUILD_PROPERTY@got_v8_revision@\"801ada225ddc271c132c3a35f03975671d43e399\"@@@",
+      "@@@SET_BUILD_PROPERTY@got_buildtools_revision@\"f0319a328b2809876916353cb994259692140934\"@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
+      "recurse",
+      "git",
+      "config",
+      "user.name",
+      "local_bot"
+    ],
+    "env": {
+      "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
+    },
+    "name": "gclient recurse (git config user.name)"
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
+      "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
+      "recurse",
+      "git",
+      "config",
+      "user.email",
+      "local_bot@example.com"
+    ],
+    "env": {
+      "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
+    },
+    "name": "gclient recurse (git config user.email)"
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
+      "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
       "runhooks"
     ],
     "cwd": "[SLAVE_BUILD]/src",
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json",
       "GYP_DEFINES": "component=static_library gomadir='[BUILD]/goma' linux_strip_binary=1 target_arch=x64 use_goma=1",
       "GYP_GENERATORS": "ninja",
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "gclient runhooks"
@@ skipping 45 matching lines @@
       "12345"
     ],
     "name": "archive_build"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]