Use a valid /prefetch argument when launching a process.

chrome/browser/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//chrome/common/features.gni")
 import("//media/media_options.gni")
@@ skipping 144 matching lines @@
     "//components/renderer_context_menu",
     "//components/search",
     "//components/search_engines",
     "//components/search_provider_logos",
     "//components/security_interstitials/core",
     "//components/security_state",
     "//components/signin/core/browser",
     "//components/ssl_errors",
     "//components/startup_metric_utils/browser:lib",
     "//components/startup_metric_utils/browser:message_filter_lib",
+
+    # TODO(fdoray): Remove this once the PreRead field trial has expired.
+    # crbug.com/577698
+    "//components/startup_metric_utils/common",
     "//components/strings",
     "//components/suggestions",
     "//components/sync_bookmarks",
     "//components/sync_driver",
     "//components/sync_sessions",
     "//components/tracing:startup_tracing",
     "//components/translate/core/browser",
     "//components/translate/core/common",
     "//components/ui/zoom",
     "//components/undo",
@@ skipping 1157 matching lines @@
         rebase_path(gypi_values.chrome_browser_rlz_sources, ".", "//chrome")
     deps = [
       "//components/google/core/browser",
       "//components/omnibox/browser",
       "//components/rlz",
       "//components/search_engines",
       "//rlz:rlz_lib",
     ]
   }
 }