GN: Autodetect Visual Studio versions

build/config/win/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.
 
+import("//build/config/win/visual_studio_version.gni")
+
 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"
-
-  # Full path to the Visual Studio installation, not including a backslash
-  # at the end.
-  visual_studio_path = "C:\Program Files (x86)\Microsoft Visual Studio 10.0"
 }
 
 # Compiler setup for the Windows SDK. Applied to all targets.
 config("sdk") {
   # The include path is the stuff returned by the script.
   #include_dirs = msvc_config[0]  TODO(brettw) make this work.
 
   defines = [
     "_ATL_NO_OPENGL",
     "_SECURE_ATL",
@@ skipping 114 matching lines @@
 }
 
 # Incremental linking ----------------------------------------------------------
 
 config("incremental_linking") {
   ldflags = [ "/INCREMENTAL" ]
 }
 config("no_incremental_linking") {
   ldflags = [ "/INCREMENTAL:NO" ]
 }