SDK stuff: Add a script to download the mojom parser binary.

sdk_build/data/common/download_mojom_parser.sh

Index: sdk_build/data/common/download_mojom_parser.sh
diff --git a/sdk_build/data/common/download_mojom_parser.sh b/sdk_build/data/common/download_mojom_parser.sh
new file mode 100755
index 0000000000000000000000000000000000000000..5051e77176ac7e1792f40d2ca861b1a80b122749
--- /dev/null
+++ b/sdk_build/data/common/download_mojom_parser.sh
@@ -0,0 +1,29 @@
+#!/bin/bash
+# Copyright 2016 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.
+
+# Note: In the SDK, this script lives in third_party/mojo_sdk_setup.
+SCRIPT_DIR=$(dirname $0)
+DOWNLOADER=${SCRIPT_DIR}/download_file_from_google_storage.py
+
+UNAME=$(uname)
+case "$UNAME" in
+  Linux)
+    # TODO(vtl): We currently just always assume 64-bit.
+    HOST_ARCH=linux64
+    ;;
+  Darwin)
+    HOST_ARCH=mac64
+    ;;
+  *)
+    echo "$0: unknown system: ${UNAME}" 1>&2
+    ;;
+esac
+
+FILE=${SCRIPT_DIR}/../mojo/public/tools/bindings/mojom_parser/bin/${HOST_ARCH}/mojom_parser
+HASH=$(cat "${FILE}.sha1")
+# This includes the bucket name first.
+GS_NAME=mojo/mojom_parser/${HOST_ARCH}/${HASH}
+
+"$DOWNLOADER" --sha1-hash="${HASH}" --executable "$GS_NAME" "$FILE"