Use src-side launcher for telemetry_unittests in chromium_trybot recipe

scripts/slave/recipes/chromium_trybot.expected/runhooks_failure.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]\\scripts\\slave\\bot_update.py",
       "--master",
       "tryserver.chromium.win",
       "--builder",
       "win_chromium_rel",
@@ skipping 109 matching lines @@
       "@@@STEP_LOG_LINE@json.output@    \"test\": \"browser_tests\"@@@",
       "@@@STEP_LOG_LINE@json.output@  }@@@",
       "@@@STEP_LOG_LINE@json.output@]@@@",
       "@@@STEP_LOG_END@json.output@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
+      "[SLAVE_BUILD]\\src\\testing\\scripts\\get_compile_targets.py",
+      "--output",
+      "/path/to/tmp/json",
+      "--",
+      "--build-config-fs",
+      "Release",
+      "--paths",
+      "{\"build\": \"[BUILD]\"}",
+      "--properties",
+      "{\"buildername\": \"win_chromium_rel\", \"buildnumber\": 571, \"slavename\": \"TestSlavename\"}"
+    ],
+    "name": "get compile targets for scripts",
+    "~followup_annotations": [
+      "@@@STEP_LOG_LINE@json.output@{}@@@",
+      "@@@STEP_LOG_END@json.output@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
       "[DEPOT_TOOLS]\\gclient.py",
       "runhooks"
     ],
     "env": {
       "GYP_DEFINES": "chromium_win_pch=0 component=static_library dcheck_always_on=1 fastbuild=1 gomadir='[BUILD]\\goma' target_arch=ia32 use_goma=1"
     },
     "name": "gclient runhooks (with patch)",
     "~followup_annotations": [
       "step returned non-zero exit code: 1",
       "@@@STEP_FAILURE@@@"
@@ skipping 81 matching lines @@
       "@@@STEP_FAILURE@@@",
       "@@@SET_BUILD_PROPERTY@failure_type@\"TRANSIENT_FAILURE\"@@@"
     ]
   },
   {
     "name": "$final_result",
     "reason": "Step('gclient runhooks (without patch)') failed with return_code 1",
     "status_code": 1
   }
 ]