Fix minor issue with build/android/envsetup.sh

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 117 matching lines @@
 }
 
 
 ################################################################################
 # Exports common GYP variables based on variable DEFINES and CHROME_SRC.
 ################################################################################
 common_gyp_vars() {
   export GYP_DEFINES="${DEFINES}"
 
   # Set GYP_GENERATORS to ninja if it's currently unset or null.
-  if [ -z $GYP_GENERATORS ]; then
+  if [ -z "$GYP_GENERATORS" ]; then
     echo "Defaulting GYP_GENERATORS to ninja."
     GYP_GENERATORS=ninja
   elif [ "$GYP_GENERATORS" != "ninja" ]; then
     echo "Warning: GYP_GENERATORS set to '$GYP_GENERATORS'."
     echo "Only GYP_GENERATORS=ninja has continuous coverage."
   fi
   export GYP_GENERATORS
 
   # Use our All target as the default
   export GYP_GENERATOR_FLAGS="${GYP_GENERATOR_FLAGS} default_target=All"
@@ skipping 130 matching lines @@
   export GYP_DEFINES="${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"
 }