Copy cdb.exe into telemetry_chrome_test's isolate.

chrome/breakpad.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.
 {
   'variables': {
     'files': [
       '../components/crash/content/tools/generate_breakpad_symbols.py',
     ],
   },
   'conditions': [
     ['OS=="linux"', {
       'variables': {
         'files': [
           '<(PRODUCT_DIR)/dump_syms',
         ],
       },
     }],
     ['OS=="mac"', {
       'variables': {
         'files': [
           '<(PRODUCT_DIR)/crashpad_database_util',
           '<(PRODUCT_DIR)/dump_syms',
         ],
       },
     }],
     ['OS=="win"', {
       'variables': {
         'files': [
+          '<(PRODUCT_DIR)/cdb<(EXECUTABLE_SUFFIX)',
           '<(PRODUCT_DIR)/crashpad_database_util<(EXECUTABLE_SUFFIX)',
         ],
       },
     }],
   ],
 }