Specify GYP variable archive_gpu_tests=1 on GPU bots.

scripts/slave/recipes/gpu/build_and_upload.expected/win_debug.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]\\scripts\\slave\\cleanup_temp.py"
     ],
     "name": "cleanup temp"
   },
   {
@@ skipping 98 matching lines @@
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "[DEPOT_TOOLS]\\gclient.py",
       "runhooks"
     ],
     "env": {
-      "GYP_DEFINES": "blink_asserts_always_on=1 chromium_win_pch=0 component=shared_library dcheck_always_on=1 fastbuild=1 gomadir='[BUILD]\\goma' internal_gles2_conform_tests=1 target_arch=ia32 test_isolation_mode=archive test_isolation_outdir=https://isolateserver.appspot.com use_goma=1"
+      "GYP_DEFINES": "archive_gpu_tests=1 blink_asserts_always_on=1 chromium_win_pch=0 component=shared_library dcheck_always_on=1 fastbuild=1 gomadir='[BUILD]\\goma' internal_gles2_conform_tests=1 target_arch=ia32 test_isolation_mode=archive test_isolation_outdir=https://isolateserver.appspot.com use_goma=1"
     },
     "name": "gclient runhooks"
   },
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]\\scripts\\slave\\compile.py",
       "--target",
       "Debug",
@@ skipping 34 matching lines @@
       "@@@STEP_LOG_LINE@json.output@  \"gl_tests\": \"[dummy hash for gl_tests]\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"gles2_conform_test\": \"[dummy hash for gles2_conform_test]\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"tab_capture_end2end_tests\": \"[dummy hash for tab_capture_end2end_tests]\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"telemetry_gpu_test\": \"[dummy hash for telemetry_gpu_test]\"@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@",
       "@@@SET_BUILD_PROPERTY@swarm_hashes@{\"content_gl_tests\": \"[dummy hash for content_gl_tests]\", \"tab_capture_end2end_tests\": \"[dummy hash for tab_capture_end2end_tests]\", \"gles2_conform_test\": \"[dummy hash for gles2_conform_test]\", \"gl_tests\": \"[dummy hash for gl_tests]\", \"angle_unittests\": \"[dummy hash for angle_unittests]\", \"telemetry_gpu_test\": \"[dummy hash for telemetry_gpu_test]\"}@@@"
     ]
   }
 ]