Build PPAPI NaCl Glibc tests with GN

Support building PPAPI NaCl tests with GCC/Glibc-based toolchain.

BUG=462791

Review URL: https://codereview.chromium.org/1333673002

Cr-Original-Commit-Position: refs/heads/master@{#350467}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 70a330fb376e614a401e738f6e7442674b0052bd

config/nacl/config.gni

@@ -0,0 +1,10 @@
+# Copyright 2015 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.
+
+declare_args() {
+  # Native Client supports both Newlib and Glibc C libraries where Newlib
+  # is assumed to be the default one; use this to determine whether Glibc
+  # is being used instead.
+  is_nacl_glibc = false
+}

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/config/sanitizers/sanitizers.gni")
 import("//build/toolchain/toolchain.gni")
 
@@ -70,6 +71,8 @@ concurrent_links = exec_script("get_concurrent_links.py", [], "value")
 #      Whether to forcibly enable or disable component builds for this
 #      toolchain; if not specified, the toolchain will inherit the
 #      default setting.
+#  - is_nacl_glibc
+#      Whether NaCl code is built using Glibc instead of Newlib.
 template("gcc_toolchain") {
   toolchain(target_name) {
     assert(defined(invoker.cc), "gcc_toolchain() must specify a \"cc\" value")
@@ -320,6 +323,7 @@ template("gcc_toolchain") {
                              [
                                "is_clang",
                                "is_component_build",
+                               "is_nacl_glibc",
                              ])
 
       if (defined(invoker.clear_sanitizers) && invoker.clear_sanitizers) {

toolchain/nacl/BUILD.gn

@@ -50,6 +50,7 @@ nacl_toolchain("glibc_x86") {
   toolchain_cpu = "x86"
   toolprefix = "${os_toolchain_dir}/${toolchain_package}/bin/i686-nacl-"
   is_clang = false
+  is_nacl_glibc = true
 
   cc = toolprefix + "gcc"
   cxx = toolprefix + "g++"
@@ -63,6 +64,7 @@ nacl_toolchain("glibc_x64") {
   toolchain_cpu = "x64"
   toolprefix = "${os_toolchain_dir}/${toolchain_package}/bin/x86_64-nacl-"
   is_clang = false
+  is_nacl_glibc = true
 
   cc = toolprefix + "gcc"
   cxx = toolprefix + "g++"

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.
@@ -38,6 +39,7 @@ template("nacl_toolchain") {
                              "cxx",
                              "deps",
                              "is_clang",
+                             "is_nacl_glibc",
                              "ld",
                              "link_outputs",
                              "postlink",