Build PPAPI NaCl Glibc tests with GN

build/toolchain/nacl_toolchain.gni

Index: build/toolchain/nacl_toolchain.gni
diff --git a/build/toolchain/nacl_toolchain.gni b/build/toolchain/nacl_toolchain.gni
index ab3b693a142e3f5575a46e0fd71a2aa2c3c9cc12..cf1d14b96b559919e704e9dfd0bb05145127d52a 100644
--- a/build/toolchain/nacl_toolchain.gni
+++ b/build/toolchain/nacl_toolchain.gni
@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/nacl/config.gni")
 import("//build/toolchain/gcc_toolchain.gni")
 
 # This template defines a NaCl toolchain.
@@ -48,6 +49,8 @@ template("nacl_toolchain") {
   # We do not wish to suport shared builds with the NaCl toolchains.
   is_component_build = false
 
+  is_nacl_glibc = invoker.is_nacl_glibc
+
   gcc_toolchain(target_name) {
     rebuild_define = "NACL_TC_REV=" + invoker.toolchain_revision
     if (defined(invoker.deps)) {