Added GYP defines to dump linux symbols for gpu perf bots and trybots.

scripts/slave/recipes/blink_trybot.expected/blink_platform_unittests_failure.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
       "tryserver.blink",
       "--builder",
       "linux_blink_rel",
@@ skipping 80 matching lines @@
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "[DEPOT_TOOLS]/gclient.py",
       "runhooks"
     ],
     "env": {
-      "GYP_DEFINES": "archive_gpu_tests=1 component=static_library dcheck_always_on=1 fastbuild=1 gomadir='[BUILD]/goma' target_arch=x64 test_isolation_mode=prepare use_goma=1"
+      "GYP_DEFINES": "archive_gpu_tests=1 component=static_library dcheck_always_on=1 fastbuild=1 gomadir='[BUILD]/goma' linux_dump_symbols=1 target_arch=x64 test_isolation_mode=prepare use_goma=1"
     },
     "name": "gclient runhooks"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[isolate]/resources/find_isolated_tests.py",
       "--build-dir",
       "[SLAVE_BUILD]/src/out/Release",
@@ skipping 176 matching lines @@
       "@@@STEP_LOG_END@python.inline@@@",
       "@@@SET_BUILD_PROPERTY@failure_hash@\"63f155d4140188330495bb0598aa87ddf3ddce38\"@@@"
     ]
   },
   {
     "name": "$final_result",
     "reason": "Step('blink_platform_unittests') failed with return_code 1",
     "status_code": 1
   }
 ]