Update Android build to API level 17 and SDK Tools version 21

build/android/envsetup.sh

 # 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.  It can either be
 # compiled with the Android tree or using the Android SDK/NDK. To build with
 # NDK/SDK: ". build/android/envsetup.sh".  Environment variable
 # ANDROID_SDK_BUILD=1 will then be defined and used in the rest of the setup to
 # specifiy build type.
 
@@ skipping 63 matching lines @@
   # If current directory is not in $CHROME_SRC, it might be set for other
   # source tree. If $CHROME_SRC was set correctly and we are in the correct
   # directory, "${CURRENT_DIR/"${CHROME_SRC}"/}" will be "".
   # Otherwise, it will equal to "${CURRENT_DIR}"
   echo "Warning: Current directory is out of CHROME_SRC, it may not be \
 the one you want."
   echo "${CHROME_SRC}"
 fi
 
 # Android sdk platform version to use
-export ANDROID_SDK_VERSION=16
+export ANDROID_SDK_VERSION=17
 
 if [[ "${ANDROID_SDK_BUILD}" -eq 1 ]]; then
   if [[ -z "${TARGET_ARCH}" ]]; then
     return 1
   fi
   sdk_build_init
 # Sets up environment for building Chromium for Android with source. Expects
 # android environment setup and lunch.
 elif [[ -z "$ANDROID_BUILD_TOP" || \
         -z "$ANDROID_TOOLCHAIN" || \
@@ skipping 34 matching lines @@
   # This is just a simple wrapper of gyp_chromium, please don't add anything
   # in this function.
   echo "GYP_GENERATORS set to '$GYP_GENERATORS'"
   (
     "${CHROME_SRC}/build/gyp_chromium" --depth="${CHROME_SRC}" --check "$@"
   )
 }
 
 # FLOCK needs to be null on system that has no flock
 which flock > /dev/null || export FLOCK=