Use a single cros_toolchain tarball for ChromeOS build

platform_tools/chromeos/bin/chromeos_make

 #!/bin/bash
 
 # This script builds Skia for ChromeOS by mounting the Skia checkout inside a
 # chroot contained within an existing ChromeOS checkout, entering the chroot,
 # and running the build_skia_in_chroot script.
 
 SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 
 if [ $(uname) != "Linux" ]; then
     echo "ERROR: Can only build for ChromeOS on Linux."
     exit 1
 fi
 
 
 makeVars=""
 deviceID=""
-crosBotoFile=""
 
 while (( "$#" )); do
 
   if [[ $(echo "$1" | grep "^-d$") != "" ]];
   then 
     deviceID="$2"
     shift
-  elif [[ "$1" == "--cros-boto-file" ]];
-  then
-    crosBotoFile="$2"
-    shift
   else
     makeVars="$makeVars $1"
   fi
 
 shift
 done
 
 if [[ -z "${deviceID}" ]]; then
   echo "You must provide a deviceID with -d."
   exit 1
 fi
 
 CHROMEOS_CHROOT="${SCRIPT_DIR}/../toolchain"
 
-# Obtain some extra headers and libraries if needed.
-if ! [[ -d "${CHROMEOS_CHROOT}/x86-generic" && \
-        -d "${CHROMEOS_CHROOT}/amd64-generic" && \
-        -d "${CHROMEOS_CHROOT}/arm-generic" ]]; then
-  gsutil cp gs://chromium-skia-gm/chromeos-toolchains/cros_toolchain.tgz ${CHROMEOS_CHROOT}
-  if [[ "$?" != "0" ]]; then
-    exit 1
-  fi
-  pushd ${CHROMEOS_CHROOT} > /dev/null
-  tar -zxvf cros_toolchain.tgz
-  if [[ "$?" != "0" ]]; then
-    exit 1
-  fi
-  rm cros_toolchain.tgz
-  popd > /dev/null
-fi
-
-# If a boto file was provided, use that instead of the default.
-if [[ -n "$crosBotoFile" ]]; then
-  export AWS_CREDENTIAL_FILE="$crosBotoFile"
-  export BOTO_CONFIG="$crosBotoFile"
-fi
-
 # Get the required SDK version.
 # TODO(borenet): Should we instead get the latest from GS?
 #SDK_VERSION=$(gsutil cat gs://chromeos-image-archive/${deviceID}-release/LATEST-master)
 #SDK_VERSION=${SDK_VERSION:4}
 SDK_VERSION="4279.0.0"
 mkdir -p "${CHROMEOS_CHROOT}/src/chromeos"
 echo -n ${SDK_VERSION} > "${CHROMEOS_CHROOT}/src/chromeos/CHROMEOS_LKGM"
 
+# Download the toolchain tarball if needed.
+# TODO(borenet): Let chrome-sdk take care of this once it works with external
+# boards.
+if ! [[ -d "${CHROMEOS_CHROOT}/.cros_cache" ]]; then
+  TARBALL="cros_toolchain.tgz"
+  gsutil cp gs://chromium-skia-gm/chromeos-toolchains/${TARBALL} ${CHROMEOS_CHROOT}
+  if [ "$?" != "0" ]
+  then
+    exit 1;
+  fi
+  pushd "${CHROMEOS_CHROOT}" > /dev/null
+  tar -zxvf ${TARBALL}
+  popd > /dev/null
+  rm ${CHROMEOS_CHROOT}/${TARBALL}
+fi
+
 # Put a fake .gclient file in the toolchain directory so that the cros tool
 # thinks we're in a Chrome checkout.
 echo "Delete me!" > "${CHROMEOS_CHROOT}/.gclient"
 
 # Where the Skia code will pretend to live inside the chroot.
 SKIA_TOP_DIR="${SCRIPT_DIR}/../../.."
 
 pushd ${CHROMEOS_CHROOT}
 cros chrome-sdk --board ${deviceID} --debug -- /bin/sh -c "cd ${SKIA_TOP_DIR}; platform_tools/chromeos/bin/build_skia_in_chroot ${makeVars}"
 returnVal=$?
 popd > /dev/null
 
 # Clean up
 rm ${CHROMEOS_CHROOT}/.gclient
 
 if [ "${returnVal}" != "0" ]
 then
   exit 1;
 fi