Laying the groundwork for targeting WinRT.

build/config/compiler/BUILD.gn

Index: build/config/compiler/BUILD.gn
diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index 30872ae61d1bd5a592eb54e2185d586e4144a3af..3790c6a62dec8aeece58276e2d385885b87760bf 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -574,13 +574,20 @@ config("runtime_library") {
       }
     }
   } 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" ]
+      }
     }
   }