Add chrome perf tests and sniffer to GN build.

BUILD.gn

 # Copyright (c) 2013 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.
 
 # This is the root build file for GN. GN will start processing by loading this
 # file, and recursively load all dependencies until all dependencies are either
 # resolved or known not to exist (which will cause the build to fail). So if
 # you add a new build file, there must be some path of dependencies from this
 # file to your new one or GN won't know about it.
 
@@ skipping 20 matching lines @@
   deps = [
     "//apps",
     "//ash",
     "//cc",
     "//cc/blink",
     "//chrome/browser",
     "//chrome/browser/devtools",
     "//chrome/common",
     "//chrome/plugin",
     "//chrome/renderer",
+    "//chrome/test",
+    "//chrome/tools",
     "//chrome/utility",
     "//components:all_components",
     "//content",
     "//content/shell:content_shell",
     "//content/test:test_support",
     "//crypto",
     "//device/battery",
     "//device/bluetooth",
     "//device/nfc",
     "//extensions/browser",
@@ skipping 198 matching lines @@
     ]
   }
 
   # Non-mobile builds.
   if (!is_android && !is_ios) {
     deps += [
       "//device/usb",
     ]
   }
 }