Laying the groundwork for targeting WinRT.

build/config/compiler/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/android/config.gni")
 import("//build/config/chrome_build.gni")
 if (current_cpu == "arm") {
   import("//build/config/arm.gni")
 }
 if (current_cpu == "mipsel" || current_cpu == "mips64el") {
@@ skipping 556 matching lines @@
     if (is_win) {
       # Since the library is shared, it requires exceptions or will give errors
       # about things not matching, so keep exceptions on.
       if (is_debug) {
         cflags += [ "/MDd" ]
       } else {
         cflags += [ "/MD" ]
       }
     }
   } else {
-    # Static CRT.
-    if (is_win) {
+    if (is_win && current_os == "win") {

[brettw, 2015/07/22 20:29:20]

This line reads very strangely to me since they seem to be saying the same
thing. Maybe swap these two cases, and be sure to put a WinRT comment first, so
it's

  if (is_win && current_os != "win") {
    # WindowsRT: use the dynamic CRT.
    ...
  } else {
    # Desktop Windows.
    ...
  }

+      # Static CRT.
       if (is_debug) {
         cflags += [ "/MTd" ]
       } else {
         cflags += [ "/MT" ]
       }
+    } else if (is_win) {
+      # Dynamic CRT on WinRT.
+      if (is_debug) {
+        cflags += [ "/MDd" ]
+      } else {
+        cflags += [ "/MD" ]
+      }
     }
   }
 
   if (is_win) {
     defines += [
       "__STD_C",
       "_CRT_RAND_S",
       "_CRT_SECURE_NO_DEPRECATE",
       "_HAS_EXCEPTIONS=0",
       "_SCL_SECURE_NO_DEPRECATE",
@@ skipping 571 matching lines @@
       cflags += [ "-gsplit-dwarf" ]
     }
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }