Add flutter/gallery to flutter-analyze bot

Fixes https://github.com/dart-lang/sdk/issues/47527

Change-Id: I24a7b20f9756197a058eefd507dc139d19762642
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/222660
Reviewed-by: Alexander Thomas <athom@google.com>
Reviewed-by: Devon Carew <devoncarew@google.com>
Commit-Queue: Samuel Rawlins <srawlins@google.com>

tools/bots/flutter/analyze_flutter_gallery.sh

@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+# Copyright (c) 2021, the Dart project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+# Analyze Dart code in the flutter/gallery repo.
+
+set -ex
+
+checkout=$(pwd)
+dart=$checkout/out/ReleaseX64/dart-sdk/bin/dart
+sdk=$checkout/out/ReleaseX64/dart-sdk
+tmpdir=$(mktemp -d)
+cleanup() {
+  rm -rf "$tmpdir"
+}
+trap cleanup EXIT HUP INT QUIT TERM PIPE
+cd "$tmpdir"
+
+# install flutter
+git clone --single-branch -vv https://github.com/flutter/flutter
+export PATH="$PATH":"$tmpdir/flutter/bin"
+flutter --version
+
+git clone --single-branch -vv \
+  https://dart.googlesource.com/external/github.com/flutter/gallery
+
+cd gallery
+
+# analyze
+echo Analyzing...
+
+flutter packages get
+$dart analyze --fatal-infos

tools/bots/test_matrix.json

@@ -3753,6 +3753,10 @@
         {
           "name": "analyze flutter/plugins",
           "script": "tools/bots/flutter/analyze_flutter_plugins.sh"
+        },
+        {
+          "name": "analyze flutter/gallery",
+          "script": "tools/bots/flutter/analyze_flutter_gallery.sh"
         }
       ]
     },