Second attempt at fixing Ninja build for Android and change make for host os optionally use goma

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 104 matching lines @@
       return 1
   esac
 }
 
 
 ################################################################################
 # Exports common GYP variables based on variable DEFINES and CHROME_SRC.
 ################################################################################
 common_gyp_vars() {
   export GYP_DEFINES="${DEFINES}"
-  export GYP_GENERATORS="make-android"
+  if [[ -z "${GYP_GENERATORS}" ]]; then
+    export GYP_GENERATORS="make-android"
+  fi
 
   # Use our All target as the default
   export GYP_GENERATOR_FLAGS="${GYP_GENERATOR_FLAGS} default_target=All"
 
   # We want to use our version of "all" targets.
   export CHROMIUM_GYP_FILE="${CHROME_SRC}/build/all_android.gyp"
 }
 
 
 ################################################################################
@@ skipping 140 matching lines @@
 
   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"
 
   # TODO(torne): This isn't upstream yet. Upstream it or remove this setting.
   export CHROMIUM_GYP_FILE="${CHROME_SRC}/build/all_android_webview.gyp"
 }