Update references to tools/telemetry in .gn, .gyp & .isolate files

chrome/telemetry_gpu_unittests.isolate

 # 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.
 {
-  'includes': [
-    '../tools/telemetry/telemetry.isolate',
-  ],
   'conditions': [
     ['OS=="android" or OS=="linux" or OS=="mac" or OS=="win"', {
       'variables': {
         'files': [
           # Other dependencies of the tests and their harness.
           '../third_party/typ/',
           '../third_party/catapult/',
           '../testing/test_env.py',
           '../testing/xvfb.py',
           '../testing/scripts/common.py',
           '../testing/scripts/run_telemetry_as_googletest.py',
           # The following represent the actual tests.
           '../content/test/gpu/',
           # For resolve the imports in content/test/gpu/run_gpu_test.py
           '../tools/perf/chrome_telemetry_build/',
           # For webgl_conformance_expectations_unittest
           '../third_party/webgl/src/sdk/tests/',
         ],
         'command': [
           '../testing/scripts/run_telemetry_as_googletest.py',
           '../content/test/gpu/run_unittests.py',
           '-v',
         ],
       },
     }],
   ]
 }