Remove 'read_only': 1 from most .isolate files.

chrome/browser_tests.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': [
     ['use_x11==0', {
       'variables': {
         'command': [
           '../testing/test_env.py',
           '<(PRODUCT_DIR)/browser_tests<(EXECUTABLE_SUFFIX)',
@@ skipping 80 matching lines @@
           '<(PRODUCT_DIR)/test_data/',
           '<(PRODUCT_DIR)/test_page.css',
           '<(PRODUCT_DIR)/test_page.css.mock-http-headers',
           '<(PRODUCT_DIR)/test_url_loader_data/',
           'browser/policy/test/asn1der.py',
           'browser/policy/test/policy_testserver.py',
           'common/extensions/docs/examples/apps/calculator/',
           'test/data/',
           'third_party/mock4js/',
         ],
-        'read_only': 1,
       },
     }],
     ['disable_nacl==0 and (OS=="linux" or OS=="mac" or OS=="win")', {
       'variables': {
         'files': [
           '<(PRODUCT_DIR)/nacl_test_data/',
           '<(PRODUCT_DIR)/pnacl/',
           '<(PRODUCT_DIR)/ppapi_nacl_tests_newlib.nmf',
           '<(PRODUCT_DIR)/ppapi_nacl_tests_pnacl.nmf',
         ],
-        'read_only': 1,
       },
     }],
     ['OS=="linux" or OS=="win"', {
       'variables': {
         'files': [
           '../third_party/bidichecker/',
         ],
       },
     }],
     ['disable_nacl==0 and (OS=="linux" or OS=="win")', {
@@ skipping 140 matching lines @@
           'browser/chromeos/login/test/https_forwarder.py',
         ],
       },
     }],
   ],
   'includes': [
     '../base/base.isolate',
     'chrome.isolate',
   ],
 }