Allow specification of a non-default boto file in chromeos_make

platform_tools/chromeos/bin/chromeos_make

Index: platform_tools/chromeos/bin/chromeos_make
===================================================================
--- platform_tools/chromeos/bin/chromeos_make	(revision 9684)
+++ platform_tools/chromeos/bin/chromeos_make	(working copy)
@@ -14,6 +14,7 @@
 
 makeVars=""
 deviceID=""
+crosBotoFile=""
 
 while (( "$#" )); do
 
@@ -21,6 +22,10 @@
   then 
     deviceID="$2"
     shift
+  elif [[ "$1" == "--cros-boto-file" ]];
+  then
+    crosBotoFile="$2"
+    shift
   else
     makeVars="$makeVars $1"
   fi
@@ -52,6 +57,12 @@
   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)