Support Git in pub global activate.

sdk/lib/_internal/pub/test/global/activate/reactivating_git_upgrades_test.dart

Index: sdk/lib/_internal/pub/test/global/activate/reactivating_git_upgrades_test.dart
diff --git a/sdk/lib/_internal/pub/test/global/activate/reactivating_git_upgrades_test.dart b/sdk/lib/_internal/pub/test/global/activate/reactivating_git_upgrades_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..6a25d23fe898464a28b104b7a634e3d092104785
--- /dev/null
+++ b/sdk/lib/_internal/pub/test/global/activate/reactivating_git_upgrades_test.dart
@@ -0,0 +1,34 @@
+// Copyright (c) 2014, 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.
+
+import '../../descriptor.dart' as d;
+import '../../test_pub.dart';
+
+main() {
+  initConfig();
+  integration('ignores previously activated git commit',
+        () {
+    ensureGit();
+
+    d.git('foo.git', [
+      d.libPubspec("foo", "1.0.0")
+    ]).create();
+
+    schedulePub(args: ["global", "activate", "-sgit", "../foo.git"],
+        output: '''
+Resolving dependencies...
+Activated foo 1.0.0 from Git repository "../foo.git".''');
+
+    d.git('foo.git', [
+      d.libPubspec("foo", "1.0.1")
+    ]).commit();
+
+    // Activating it again pulls down the latest commit.
+    schedulePub(args: ["global", "activate", "-sgit", "../foo.git"],
+        output: '''
+Package foo is currently active from Git repository "../foo.git".
+Resolving dependencies...
+Activated foo 1.0.1 from Git repository "../foo.git".''');
+  });
+}