Hook up use_system_libjpeg for Android

build/android/envsetup.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.
 
 # Sets up environment for building Chromium on Android. Only Android NDK,
 # Revision 6b on Linux or Mac is offically supported.
 #
 # To run this script, the system environment ANDROID_NDK_ROOT must be set
@@ skipping 121 matching lines @@
   echo "GYP_GENERATORS set to '$GYP_GENERATORS'"
   "${CHROME_SRC}/build/gyp_chromium" --depth="${CHROME_SRC}" "$@"
 }
 
 export OBJCOPY=$(echo ${ANDROID_TOOLCHAIN}/*-objcopy)
 export STRIP=$(echo ${ANDROID_TOOLCHAIN}/*-strip)
 
 # The set of GYP_DEFINES to pass to gyp. Use 'readlink -e' on directories
 # to canonicalize them (remove double '/', remove trailing '/', etc).
 DEFINES+=" OS=android"
-DEFINES+=" android_build_type=0"  # Currently, Only '0' is supportted.
+DEFINES+=" android_build_type=0"
 DEFINES+=" host_os=${host_os}"
 DEFINES+=" linux_fpic=1"
 DEFINES+=" release_optimize=s"
 DEFINES+=" linux_use_tcmalloc=0"
 DEFINES+=" disable_nacl=1"
 DEFINES+=" remoting=0"
 DEFINES+=" p2p_apis=0"
 DEFINES+=" enable_touch_events=1"
 DEFINES+=" build_ffmpegsumo=0"
 DEFINES+=" gtest_target_type=shared_library"
 DEFINES+=" branding=Chromium"
 DEFINES+=\
 " android_sdk=${ANDROID_SDK_ROOT}/platforms/android-${ANDROID_SDK_VERSION}"
 DEFINES+=" android_sdk_tools=${ANDROID_SDK_ROOT}/platform-tools"
 
 export GYP_DEFINES="${DEFINES}"
 
 # Use the "android" flavor of the Makefile generator for both Linux and OS X.
 export GYP_GENERATORS="make-android"
 
 # 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"