Instrumented libraries: add a base.isolate entry for prebuilt libs.

third_party/instrumented_libraries/instrumented_libraries.isolate

 # Copyright 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.
-
 {
-  'includes': [
-    '../../legion.isolate'
-  ],
   'conditions': [
-    ['multi_machine == 1', {
+    ['use_instrumented_libraries==1', {
       'variables': {
-        'command': [
-          'python',
-          '../../run_task.py',
+        'files': [
+          '<(PRODUCT_DIR)/instrumented_libraries/',
         ],
+      },
+    }],
+    ['use_prebuilt_instrumented_libraries==1', {
+      'variables': {
         'files': [
-          'task_test.isolate',
-          'task_test.py',
+          '<(PRODUCT_DIR)/instrumented_libraries_prebuilt/',
         ],
       },
     }],
   ],
 }
+