Only add pdb to isolate when fastbuild!=2.

base/base_unittests.isolate

 # Copyright (c) 2012 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=="android" or OS=="linux" or OS=="mac" or OS=="win"', {
       'variables': {
         'isolate_dependency_untracked': [
           'test/data/',
         ],
@@ skipping 26 matching lines @@
     ['OS=="mac" or OS=="win"', {
       'variables': {
         'command': [
           '../testing/test_env.py',
           '<(PRODUCT_DIR)/base_unittests<(EXECUTABLE_SUFFIX)',
           '--brave-new-test-launcher',
           '--test-launcher-bot-mode',
         ],
       },
     }],
-    ['OS=="win"', {
+    ['OS=="win" and (fastbuild==0 or fastbuild==1)', {
       'variables': {
-        'isolate_dependency_tracked': [
-        ],
         'isolate_dependency_untracked': [
           '<(PRODUCT_DIR)/base_unittests.exe.pdb',
         ],
       },
     }],
   ],
   'includes': [
     'base.isolate',
   ],
 }