[MIPS] Add support for Chromium-Android for MIPS build to BUILD.gn

build/toolchain/android/BUILD.gn

 # Copyright 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("../clang.gni")
 import("../goma.gni")
 import("../gcc_toolchain.gni")
 
 # Get the location of the Android tools in our tree.
 android_ndk_root =
@@ skipping 17 matching lines @@
   # any given build.
   if (is_clang) {
     # Set the GYP header for all toolchains when running under Clang.
     gyp_header = make_clang_global_settings
   } else {
     # Find the compiler for GYP for non-Clang Android.
     if (cpu_arch == "x86") {
       android_toolchain_arch = "x86-4.6"
     } else if (cpu_arch == "arm") {
       android_toolchain_arch = "arm-linux-androideabi-4.6"
+    } else if (cpu_arch == "mipsel") {
+      android_toolchain_arch = "mipsel-linux-android-4.6"
     } else {
       assert(false, "Need Android toolchain support for your platform.")
     }
 
     android_toolchain =
       "$android_ndk_root/toolchains/$android_toolchain_arch/prebuilt/$build_os-$android_host_arch/bin"
 
     # This script will find the compilers for the given Android toolchain
     # directory.
     # TODO(brettw) write this script which locates the Android compilers.
@@ skipping 44 matching lines @@
 gcc_toolchain("arm") {
   prefix = "$android_ndk_root/toolchains/arm-linux-androideabi-4.6/prebuilt/$build_os-$android_host_arch/bin/arm-linux-androideabi-"
   cc  = prefix + "gcc"
   cxx = prefix + "g++"
   ar  = prefix + "ar"
   ld  = cxx
 
   toolchain_cpu_arch = "arm"
   toolchain_os = "android"
 }
+
+gcc_toolchain("mipsel") {
+  prefix = "$android_ndk_root/toolchains/mipsel-linux-android-4.6/prebuilt/$build_os-$android_host_arch/bin/mipsel-linux-android-"
+  cc  = prefix + "gcc"
+  cxx = prefix + "g++"
+  ar  = prefix + "ar"
+  ld  = cxx
+
+  toolchain_cpu_arch = "mipsel"
+  toolchain_os = "android"
+}