Revert of Isolate extensions_browsertests

extensions/extensions_tests.gyp

 {
   'variables': {
     # Product name is used for Mac bundle.
     'app_shell_product_name': 'App Shell',
     # The version is high enough to be supported by Omaha (at least 31)
     # but fake enough to be obviously not a Chrome release.
     'app_shell_version': '38.1234.5678.9',
     'chromium_code': 1,
   },
   'targets': [
@@ skipping 212 matching lines @@
         # This is only here to keep gyp happy. This target never builds on
         # mobile platforms.
         ['OS != "ios" and OS != "android"', {
           'dependencies': [
             '<(DEPTH)/components/components.gyp:storage_monitor_test_support',
           ],
         }],
       ]
     },
   ],
-  'conditions': [
-    ['test_isolation_mode != "noop"', {
-      'targets': [
-        {
-          'target_name': 'extensions_browsertests_run',
-          'type': 'none',
-          'dependencies': [
-            'extensions_browsertests',
-          ],
-          'includes': [
-            '../build/isolate.gypi',
-          ],
-          'sources': [
-            'extensions_browsertests.isolate',
-          ],
-        },
-      ],
-    }],
-  ],
 }