Enable precompiled headers for Blink on Windows.

third_party/WebKit/Source/web/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/ui.gni")
 import("//testing/test.gni")
 import("//third_party/WebKit/Source/bindings/bindings.gni")
 import("//third_party/WebKit/Source/config.gni")
 import("//third_party/WebKit/Source/core/core.gni")
 import("//third_party/WebKit/Source/modules/modules.gni")
@@ skipping 12 matching lines @@
     "//third_party/icu",
     "//ui/gfx/geometry",
     "//v8",
   ]
 
   configs += [
     "//build/config/compiler:wexit_time_destructors",
     "//third_party/WebKit/Source:config",
     "//third_party/WebKit/Source:inside_blink",
     "//third_party/WebKit/Source:non_test_config",
+    "//third_party/WebKit/Source/core:blink_core_pch",
   ]
 
   defines = [ "BLINK_WEB_IMPLEMENTATION=1" ]
 
   sources = [
     "AssertMatchingEnums.cpp",
     "AudioOutputDeviceClientImpl.cpp",
     "AudioOutputDeviceClientImpl.h",
     "ChromeClientImpl.cpp",
     "ChromeClientImpl.h",
@@ skipping 245 matching lines @@
     "//third_party/WebKit/Source/core:testing",
     "//third_party/WebKit/Source/modules:modules_testing",
     "//third_party/WebKit/Source/wtf",
     "//v8",
   ]
 
   sources = [
     "WebTestingSupport.cpp",
   ]
 
-  configs += [ "//third_party/WebKit/Source:config" ]
+  configs += [
+    "//third_party/WebKit/Source:config",
+    "//third_party/WebKit/Source/core:blink_core_pch",
+  ]
 
   include_dirs = [ "$root_gen_dir/blink" ]
 }
 
 group("webkit_unit_tests_data") {
   data = [
     "tests/data/",
     "../core/paint/test_data/",
   ]
 }
@@ skipping 108 matching lines @@
   ]
 
   data_deps = [
     ":webkit_unit_tests_data",
     "//content/shell:pak",
   ]
 
   configs += [
     "//third_party/WebKit/Source:config",
     "//third_party/WebKit/Source:inside_blink",
+    "//third_party/WebKit/Source/core:blink_core_pch",
   ]
 
   if (is_android) {
     deps += [
       "//base:base_java",
       "//content/public/android:content_java",
       "//content/shell/android:content_shell_assets",
       "//net/android:net_java",
     ]
   }
 }