Build PPAPI NaCl Glibc tests with GN

build/toolchain/gcc_toolchain.gni

Index: build/toolchain/gcc_toolchain.gni
diff --git a/build/toolchain/gcc_toolchain.gni b/build/toolchain/gcc_toolchain.gni
index bb3846c3bb6bd817cd9b00ab770142c909203ca6..ac6df2899df7b8dcb1ff1a6c4b8f2f9fe4b017e8 100644
--- a/build/toolchain/gcc_toolchain.gni
+++ b/build/toolchain/gcc_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/toolchain.gni")
 
 # This value will be inherited in the toolchain below.
@@ -307,6 +308,9 @@ template("gcc_toolchain") {
       if (defined(invoker.is_component_build)) {
         is_component_build = invoker.is_component_build
       }
+      if (defined(invoker.is_nacl_glibc)) {
+        is_nacl_glibc = invoker.is_nacl_glibc
+      }
     }
 
     if (defined(invoker.deps)) {