Closure: enforce Java version in roll script

third_party/closure_compiler/roll_closure_compiler

 #!/bin/bash
 # Copyright 2014 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.
 #
 # Download the newest version of Closure Compiler, build it and put into Chrome
 # source tree. Also update externs/chrome_extensions.js.
 
+java -version 2>&1 | head -1 | egrep -q '\b1\.7'
+if [[ $? -ne 0 ]]; then
+  echo "This script requires Java 1.7" >&2
+  exit 1
+fi
+
+javac -version 2>&1 | egrep -q '\b1\.7'
+if [[ $? -ne 0 ]]; then
+  echo "This script requires JDK 1.7" >&2
+  exit 1
+fi
+
 readonly SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 readonly TEMP_DIR=$(mktemp -d)
 readonly EXTERNS_DIR="${SCRIPT_DIR}/externs"
 readonly README="${SCRIPT_DIR}/README.chromium"
 
 cleanup() {
   rm -rf "${TEMP_DIR}"
 }
 
 get_sha1() {
@@ skipping 110 matching lines @@
 echo "${head_range}"
 if [[ ! -z "${extensions_range}" ]]; then echo "${extensions_range}"; fi
 if [[ ! -z "${polymer_range}" ]]; then echo "${polymer_range}"; fi
 echo
 echo "TBR="
 echo "BUG='"
 echo
 echo "git cl upload"
 
 cleanup