Convert gn_unittests to run exclusively on Swarming

0 configs already ran on Swarming
3 used to run locally and were converted:
- chromium.linux.json: Linux Tests
- chromium.linux.json: Linux Tests (dbg)(1)
- chromium.linux.json: Linux Tests (dbg)(1)(32)

Ran:
  ./manage.py --convert gn_unittests

BUG=98637

Review URL: https://codereview.chromium.org/1214533005

Cr-Original-Commit-Position: refs/heads/master@{#336929}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: ddcc0a4109ccb62eeac7bd9eaf0efbc22412d8f8

tools/gn/gn.gyp

diff --git a/tools/gn/gn.gyp b/tools/gn/gn.gyp
index 639846b..2b815a7 100644
--- a/tools/gn/gn.gyp
+++ b/tools/gn/gn.gyp
@@ -274,4 +274,19 @@
       ],
     }
   ],
+  'conditions': [
+    ['test_isolation_mode != "noop"', {
+      'targets': [
+        {
+          'target_name': 'gn_unittests_run',
+          'type': 'none',
+          'dependencies': [
+            'gn_unittests',
+          ],
+          'includes': [ '../../build/isolate.gypi' ],
+          'sources': [ 'gn_unittests.isolate' ],
+        },
+      ],
+    }],
+  ],
 }

tools/gn/gn_unittests.isolate

diff --git a/tools/gn/gn_unittests.isolate b/tools/gn/gn_unittests.isolate
new file mode 100644
index 0000000..2094618
--- /dev/null
+++ b/tools/gn/gn_unittests.isolate
@@ -0,0 +1,21 @@
+# Copyright (c) 2015 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+{
+  'conditions': [
+    ['OS=="linux" or OS=="mac" or OS=="win"', {
+      'variables': {
+        'command': [
+          '<(PRODUCT_DIR)/gn_unittests<(EXECUTABLE_SUFFIX)',
+        ],
+        'files': [
+          'format_test_data/',
+          '<(PRODUCT_DIR)/gn_unittests<(EXECUTABLE_SUFFIX)',
+        ],
+      },
+    }],
+  ],
+  'includes': [
+    '../../base/base.isolate',
+  ],
+}