Make skia recipes explicitly set GIT_MODE

scripts/slave/recipes/skia/swarm_trigger.expected/Infra-PerCommit.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
       "config",
       "--spec",
-      "cache_dir = None\nsolutions = [{'deps_file': 'DEPS', 'managed': False, 'name': 'infra', 'url': 'https://skia.googlesource.com/buildbot.git'}]"
+      "cache_dir = None\nsolutions = [{'deps_file': '.DEPS.git', 'managed': False, 'name': 'infra', 'url': 'https://skia.googlesource.com/buildbot.git'}]"
     ],
     "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",
       "infra@abc123",
       "--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@    \"infra/\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": 197293@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"5e03a58dc0850e5137a8ebbce29610670c756aed\"@@@",
       "@@@STEP_LOG_LINE@json.output@    }@@@",
       "@@@STEP_LOG_LINE@json.output@  }@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@",
-      "@@@SET_BUILD_PROPERTY@got_revision@197293@@@"
+      "@@@SET_BUILD_PROPERTY@got_revision@\"5e03a58dc0850e5137a8ebbce29610670c756aed\"@@@"
     ]
   },
   {
     "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_MODULE[depot_tools::git]/resources/git_setup.py",
       "--path",
       "[SLAVE_BUILD]/swarming.client",
       "--url",
       "https://chromium.googlesource.com/external/swarming.client.git"
     ],
     "name": "git setup (swarming_client)"
   },
   {
     "cmd": [
@@ skipping 402 matching lines @@
       "--",
       "--workdir",
       "../../..",
       "skia/swarm_infra",
       "buildername=Infra-PerCommit",
       "mastername=client.skia",
       "buildnumber=5",
       "slavename=skiabot-linux-swarm-000",
       "reason=Triggered by Skia swarm_trigger Recipe",
       "swarm_out_dir=${ISOLATED_OUTDIR}",
-      "revision=197293"
+      "revision=5e03a58dc0850e5137a8ebbce29610670c756aed"
     ],
     "name": "[trigger] infra_skia on Ubuntu",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"base_task_name\": \"infra_skia/Ubuntu/def456/Infra-PerCommit/5\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"tasks\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"infra_skia/Ubuntu/def456/Infra-PerCommit/5\": {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"shard_index\": 0, @@@",
       "@@@STEP_LOG_LINE@json.output@      \"task_id\": \"10000\", @@@",
       "@@@STEP_LOG_LINE@json.output@      \"view_url\": \"https://chromium-swarm.appspot.com/user/task/10000\"@@@",
@@ skipping 64 matching lines @@
       "@@@STEP_LINK@shard #0 isolated out@blah@@@",
       "@@@STEP_LINK@view steps on Milo@https://luci-milo.appspot.com/swarming/task/148aa78d7aa0000@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]