Add precompiled headers to GN build for large targets.

content/shell/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/features.gni")
 import("//build/config/ui.gni")
 import("//build/config/win/manifest.gni")
 import("//tools/grit/repack.gni")
 import("//tools/grit/grit_rule.gni")
 if (is_android) {
@@ skipping 155 matching lines @@
     "renderer/layout_test/test_video_frame_provider.cc",
     "renderer/layout_test/test_video_frame_provider.h",
     "renderer/shell_content_renderer_client.cc",
     "renderer/shell_content_renderer_client.h",
     "renderer/shell_render_view_observer.cc",
     "renderer/shell_render_view_observer.h",
     "utility/shell_content_utility_client.cc",
     "utility/shell_content_utility_client.h",
   ]
 
-  # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
-  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
+  configs += [
+    "//build/config:precompiled_headers",
+
+    # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
+    "//build/config/compiler:no_size_t_to_int_warning",
+  ]
 
   defines = [ "CONTENT_SHELL_VERSION=\"$content_shell_version\"" ]
 
   public_deps = [
     # This exposes all public content APIs.
     "//content/public/app:both",
     "//content/public/browser",
     "//content/public/common",
     "//content/public/plugin",
     "//content/public/renderer",
@@ skipping 265 matching lines @@
 
     deps = [
       "//base",
       "//components/crash/tools:crash_service",
     ]
 
     configs -= [ "//build/config/win:console" ]
     configs += [ "//build/config/win:windowed" ]
   }
 }