Download our own copy of gradle wrapper. (#13267)

Rather than depending on android.googlesource.com for hosting the gradle
wrapper, host our own copy on storage.googleapis.com (along with our
other artifacts).

Also added a script to repackage AOSP's version into ours, in case we
ever need to update it.

Addresses the gradle wrapper part of #11681.

bin/internal/gradle_wrapper.version

-0b5c1398d1d04ac245a310de98825cb7b3278e2a
+https://storage.googleapis.com/flutter_infra/gradle-wrapper/fd5c1f2c013565a3bea56ada6df9d2b8e96d56aa/gradle-wrapper.tgz

bin/internal/repackage_gradle_wrapper.sh

+#!/bin/bash
+# Copyright 2017 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.
+
+set -e
+
+# Update this URL to get another version of the Gradle wrapper.
+# If the AOSP folks have changed the layout of their templates, you may also need to update the
+# script below to grab the right files...
+WRAPPER_SRC_URL="https://android.googlesource.com/platform/tools/base/+archive/0b5c1398d1d04ac245a310de98825cb7b3278e2a/templates.tgz"
+
+case "$(uname -s)" in
+  Darwin)
+    SHASUM="shasum"
+    ;;
+  *)
+    SHASUM="sha1sum"
+    ;;
+esac
+
+function follow_links() {
+  cd -P "${1%/*}"
+  file="$PWD/${1##*/}"
+  while [ -h "$file" ]; do
+    # On Mac OS, readlink -f doesn't work.
+    cd -P "${file%/*}"
+    file="$(readlink "$file")"
+    cd -P "${file%/*}"
+    file="$PWD/${file##*/}"
+  done
+  echo "$PWD/${file##*/}"
+}
+
+# Convert a filesystem path to a format usable by Dart's URI parser.
+function path_uri() {
+  # Reduce multiple leading slashes to a single slash.
+  echo "$1" | sed -E -e "s,^/+,/,"
+}
+
+PROG_NAME="$(path_uri "$(follow_links "$BASH_SOURCE")")"
+BIN_DIR="$(cd "${PROG_NAME%/*}" ; pwd -P)"
+FLUTTER_ROOT="$(cd "${BIN_DIR}/../.." ; pwd -P)"
+
+WRAPPER_VERSION_PATH="$FLUTTER_ROOT/bin/internal/gradle_wrapper.version"
+WRAPPER_TEMP_DIR="$FLUTTER_ROOT/bin/cache/gradle-wrapper-temp"
+
+echo "Downloading gradle wrapper..."
+rm -rf "$WRAPPER_TEMP_DIR"
+mkdir "$WRAPPER_TEMP_DIR"
+curl --continue-at - --location --output "$WRAPPER_TEMP_DIR/templates.tgz" "$WRAPPER_SRC_URL" 2>&1
+
+echo
+echo "Repackaging files..."
+mkdir "$WRAPPER_TEMP_DIR/unpack"
+tar xzf "$WRAPPER_TEMP_DIR/templates.tgz" -C "$WRAPPER_TEMP_DIR/unpack" gradle NOTICE
+
+mkdir "$WRAPPER_TEMP_DIR/repack"
+mv "$WRAPPER_TEMP_DIR/unpack/gradle/wrapper"/* "$WRAPPER_TEMP_DIR/repack/"
+mv "$WRAPPER_TEMP_DIR/unpack/NOTICE" "$WRAPPER_TEMP_DIR/repack/"
+
+pushd "$WRAPPER_TEMP_DIR/repack" > /dev/null
+STAMP=`for h in $(find . -type f); do $SHASUM $h; done | $SHASUM | cut -d' ' -f1`
+echo "Packaged files:"
+tar cvzf ../gradle-wrapper.tgz *
+popd > /dev/null
+
+echo
+echo "Uploading repackaged gradle wrapper..."
+echo "Content hash: $STAMP"
+gsutil.py cp -n "$WRAPPER_TEMP_DIR/gradle-wrapper.tgz" "gs://flutter_infra/gradle-wrapper/$STAMP/gradle-wrapper.tgz"
+
+echo "https://storage.googleapis.com/flutter_infra/gradle-wrapper/$STAMP/gradle-wrapper.tgz" > "$WRAPPER_VERSION_PATH"
+
+rm -rf "$WRAPPER_TEMP_DIR"
+echo
+echo "All done. Updated bin/internal/gradle_wrapper.version, don't forget to commit!"

packages/flutter_tools/lib/src/cache.dart

@@ -244,9 +244,8 @@ abstract class CachedArtifact {
     if (location.existsSync())
       location.deleteSync(recursive: true);
     location.createSync(recursive: true);
-    return updateInner().then<Null>((_) {
-      cache.setStampFor(name, version);
-    });
+    await updateInner();
+    cache.setStampFor(name, version);
   }
 
   /// Hook method for extra checks for being up-to-date.
@@ -410,14 +409,14 @@ class GradleWrapper extends CachedArtifact {
   GradleWrapper(Cache cache): super('gradle_wrapper', cache);
 
   @override
-  Future<Null> updateInner() async {
+  Future<Null> updateInner() {
     final Status status = logger.startProgress('Downloading Gradle Wrapper...', expectSlowOperation: true);
 
-    final String url = 'https://android.googlesource.com'
-        '/platform/tools/base/+archive/$version/templates/gradle/wrapper.tgz';
-    await _downloadZippedTarball(Uri.parse(url), location).then<Null>((_) {
+    return _downloadZippedTarball(Uri.parse(version), location).then<Null>((_) {
       // Delete property file, allowing templates to provide it.
       fs.file(fs.path.join(location.path, 'gradle', 'wrapper', 'gradle-wrapper.properties')).deleteSync();
+      // Remove NOTICE file. Should not be part of the template.
+      fs.file(fs.path.join(location.path, 'NOTICE')).deleteSync();
       status.stop();
     }).whenComplete(status.cancel);
   }