[test] Fix isolate for auto-detect in gyp

TBR=sergiyb@chromium.org

Bug: v8:6917
Change-Id: I96cedba176cd3c35ca39bb2d4604956cded114fc
Reviewed-on: https://chromium-review.googlesource.com/728023Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48740}

gni/isolate.gni

@@ -161,8 +161,6 @@ template("v8_isolate_run") {
         "--config-variable",
         "icu_use_data_file_flag=$icu_use_data_file_flag",
         "--config-variable",
-        "is_gn=1",
-        "--config-variable",
         "msan=$msan",
         "--config-variable",
         "tsan=$tsan",

gypfiles/isolate.gypi

@@ -74,7 +74,6 @@
         '--config-variable', 'gcmole=<(gcmole)',
         '--config-variable', 'has_valgrind=<(has_valgrind)',
         '--config-variable', 'icu_use_data_file_flag=<(icu_use_data_file_flag)',
-        '--config-variable', 'is_gn=0',
         '--config-variable', 'msan=<(msan)',
         '--config-variable', 'tsan=<(tsan)',
         '--config-variable', 'coverage=<(coverage)',

tools/testrunner/testrunner.isolate

@@ -7,6 +7,7 @@
       '../run-tests.py',
     ],
     'files': [
+      '<(PRODUCT_DIR)/v8_build_config.json',
       '../run-tests.py',
       './'
     ],
@@ -20,12 +21,5 @@
         ],
       },
     }],
-    ['is_gn==1', {
-      'variables': {
-        'files': [
-          '<(PRODUCT_DIR)/v8_build_config.json',
-        ],
-      },
-    }],
   ],
 }