Add GN (the build tool) to the chromium.linux buildbots and try jobs

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

Index: scripts/slave/recipes/chromium_gn.expected/unittest_basic.json
diff --git a/scripts/slave/recipes/perf/telemetry_harness_upload.expected/basic.json b/scripts/slave/recipes/chromium_gn.expected/unittest_basic.json
similarity index 74%
copy from scripts/slave/recipes/perf/telemetry_harness_upload.expected/basic.json
copy to scripts/slave/recipes/chromium_gn.expected/unittest_basic.json
index f22cee956bd97e526d532ed4718e5c8887008c05..f4aff3ffd59533ebbec2fe2f6329437599ee0536 100644
--- a/scripts/slave/recipes/perf/telemetry_harness_upload.expected/basic.json
+++ b/scripts/slave/recipes/chromium_gn.expected/unittest_basic.json
@@ -15,6 +15,17 @@
     "cmd": [
       "python",
       "-u",
+      "[BUILD]/scripts/slave/gclient_safe_revert.py",
+      ".",
+      "[DEPOT_TOOLS]/gclient"
+    ],
+    "name": "gclient revert"
+  },
+  {
+    "abort_on_failure": true,
+    "cmd": [
+      "python",
+      "-u",
       "[DEPOT_TOOLS]/gclient.py",
       "sync",
       "--nohooks",
@@ -58,38 +69,34 @@
   },
   {
     "cmd": [
-      "[SLAVE_BUILD]/src/tools/telemetry/build/generate_telemetry_harness.sh",
-      "[TMP_BASE]/telemetry-harness_tmp_1/telemetry-170242.zip"
+      "python",
+      "-u",
+      "[DEPOT_TOOLS]/gclient.py",
+      "runhooks"
     ],
-    "name": "create harness archive"
+    "env": {
+      "GYP_CHROMIUM_NO_ACTION": "1"
+    },
+    "name": "gclient runhooks"
   },
   {
     "cmd": [
       "python",
       "-u",
-      "[DEPOT_TOOLS]/third_party/gsutil/gsutil",
-      "cp",
-      "[TMP_BASE]/telemetry-harness_tmp_1/telemetry-170242.zip",
-      "gs://chromium-telemetry/snapshots/telemetry-170242.zip"
+      "[DEPOT_TOOLS]/gn.py",
+      "--root=[SLAVE_BUILD]/src",
+      "gen",
+      "//out/Debug",
+      "--args=is_debug=true"
     ],
-    "name": "gsutil upload",
-    "~followup_annotations": [
-      "@@@STEP_LINK@gsutil.upload@https://storage.cloud.google.com/chromium-telemetry/snapshots/telemetry-170242.zip@@@"
-    ]
+    "name": "gn"
   },
   {
     "cmd": [
-      "python",
-      "-u",
-      "\nimport shutil, sys\nshutil.rmtree(sys.argv[1])\n",
-      "[TMP_BASE]/telemetry-harness_tmp_1"
+      "[DEPOT_TOOLS]/ninja",
+      "-C",
+      "[SLAVE_BUILD]/src/out/Debug"
     ],
-    "name": "rmtree remove harness temp directory",
-    "~followup_annotations": [
-      "@@@STEP_LOG_LINE@python.inline@@@@",
-      "@@@STEP_LOG_LINE@python.inline@import shutil, sys@@@",
-      "@@@STEP_LOG_LINE@python.inline@shutil.rmtree(sys.argv[1])@@@",
-      "@@@STEP_LOG_END@python.inline@@@"
-    ]
+    "name": "compile"
   }
 ]