gn win: Various toolchain fixes to get compile working

build/config/win/visual_studio_version.gni

Index: build/config/win/visual_studio_version.gni
diff --git a/build/config/win/visual_studio_version.gni b/build/config/win/visual_studio_version.gni
index c0b18c73bfd4bd3c260158cd9802284a85d9f1af..24c00cd6d98a68e9e5a7faf3f8cd16b39c96fecb 100644
--- a/build/config/win/visual_studio_version.gni
+++ b/build/config/win/visual_studio_version.gni
@@ -19,7 +19,7 @@ declare_args() {
   # Full path to the Windows SDK, not including a backslash at the end.
   # This value is the default location, override if you have a different
   # installation location.
-  windows_sdk_path = "C:\Program Files (x86)\Windows Kits\8.0"
+  windows_sdk_path = "C:\Program Files (x86)\Windows Kits\8.1"
 
   # The list of include directories that are treated as "system" include
   # directories. TODO(scottmg): These are incorrectly put on the command line
@@ -34,17 +34,15 @@ if (visual_studio_path == "") {
   windows_sdk_path = toolchain_data.sdk_path
   visual_studio_version = toolchain_data.vs_version
   wdk_path = toolchain_data.wdk_dir
+  visual_studio_runtime_dirs = toolchain_data.runtime_dirs
 } else {
   assert(visual_studio_version != "",
          "You must set the visual_studio_version if you set the path")
   assert(wdk_path != "",
          "You must set the wdk_path if you set the visual studio path")
+  visual_studio_runtime_dirs = []
 }
 
-# Set when using the "Express" version of a Visual Studio version we support.
-is_visual_studio_express = (visual_studio_version == "2013e")
-
-
 # The Windows SDK include directories must be first. They both have a sal.h,
 # and the SDK one is newer and the SDK uses some newer features from it not
 # present in the Visual Studio one.
@@ -55,10 +53,3 @@ system_include_dirs = [
   "$visual_studio_path\VC\include",
   "$visual_studio_path\VC\atlmfc\include",
 ]
-
-if (is_visual_studio_express) {
-  system_include_dirs += [
-    "$wdk_path/inc/atl71",
-    "$wdk_path/inc/mfc42",
-  ]
-}