Android: allow host OS to be passed to envsetup.

build/android/envsetup_functions.sh

 #!/bin/bash
 
 # Copyright (c) 2012 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.
 
 # Defines functions for envsetup.sh which sets up environment for building
 # Chromium on Android.  The build can be either use the Android NDK/SDK or
 # android source tree.  Each has a unique init function which calls functions
 # prefixed with "common_" that is common for both environment setups.
@@ skipping 140 matching lines @@
   export CHROMIUM_GYP_FILE="${CHROME_SRC}/build/all_android.gyp"
 }
 
 
 ################################################################################
 # Prints out help message on usage.
 ################################################################################
 print_usage() {
   echo "usage: ${0##*/} [--target-arch=value] [--help]" >& 2
   echo "--target-arch=value     target CPU architecture (arm=default, x86)" >& 2
+  echo "--host-os=value         override host OS detection (linux, mac)" >&2
   echo "--try-32bit-host        try building a 32-bit host architecture" >&2
   echo "--help                  this help" >& 2
 }
 
 ################################################################################
 # Process command line options.
 # --target-arch=  Specifices target CPU architecture. Currently supported
 #                 architectures are "arm" (default), and "x86".
 # --help          Prints out help message.
 ################################################################################
 process_options() {
+  host_os=$(uname -s | sed -e 's/Linux/linux/;s/Darwin/mac/')
   try_32bit_host_build=
   while [[ $1 ]]; do
     case "$1" in
       --target-arch=*)
         target_arch="$(echo "$1" | sed 's/^[^=]*=//')"
         ;;
+      --host-os=*)
+        host_os="$(echo "$1" | sed 's/^[^=]*=//')"
+        ;;
       --try-32bit-host)
         try_32bit_host_build=true
         ;;
       --help)
         print_usage
         return 1
         ;;
       *)
         # Ignore other command line options
         echo "Unknown option: $1"
@@ skipping 91 matching lines @@
   export GYP_DEFINES="${DEFINES}"
 
   export GYP_GENERATORS="android"
 
   export GYP_GENERATOR_FLAGS="${GYP_GENERATOR_FLAGS} default_target=All"
   export GYP_GENERATOR_FLAGS="${GYP_GENERATOR_FLAGS} limit_to_target_all=1"
   export GYP_GENERATOR_FLAGS="${GYP_GENERATOR_FLAGS} auto_regeneration=0"
 
   export CHROMIUM_GYP_FILE="${CHROME_SRC}/android_webview/all_webview.gyp"
 }