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

scripts/slave/recipes/webrtc/standalone.expected/tryserver_webrtc_linux_baremetal.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
       "tryserver.webrtc",
       "--builder",
       "linux_baremetal",
@@ skipping 53 matching lines @@
     "name": "cleanup_temp"
   },
   {
     "cmd": [
       "python",
       "-u",
       "[DEPOT_TOOLS]/gclient.py",
       "runhooks"
     ],
     "env": {
-      "GYP_DEFINES": "component=static_library dcheck_always_on=1 fastbuild=1 gomadir='[BUILD]/goma' target_arch=x64 use_goma=1"
+      "GYP_DEFINES": "component=static_library dcheck_always_on=1 fastbuild=1 gomadir='[BUILD]/goma' linux_dump_symbols=1 target_arch=x64 use_goma=1"
     },
     "name": "gclient runhooks"
   },
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/compile.py",
       "--target",
       "Release",
@@ skipping 191 matching lines @@
       "{\"BUILD_CONFIG\": \"Release\", \"buildername\": \"linux_baremetal\", \"issue\": 666666, \"mastername\": \"tryserver.webrtc\", \"patchset\": 1, \"recipe\": \"webrtc/standalone\", \"revision\": \"12345\", \"rietveld\": \"https://fake.rietveld.url\", \"slavename\": \"slavename\"}",
       "--annotate=gtest",
       "--test-type=webrtc_perf_tests",
       "--builder-name=linux_baremetal",
       "--slave-name=slavename",
       "webrtc_perf_tests"
     ],
     "name": "webrtc_perf_tests"
   }
 ]