Properly update git binary snapshots during pub upgrade.

sdk/lib/_internal/pub/test/snapshot/updates_snapshot_for_git_dependency_test.dart

Index: sdk/lib/_internal/pub/test/snapshot/updates_snapshot_for_git_dependency_test.dart
diff --git a/sdk/lib/_internal/pub/test/snapshot/upgrades_snapshot_test.dart b/sdk/lib/_internal/pub/test/snapshot/updates_snapshot_for_git_dependency_test.dart
similarity index 53%
copy from sdk/lib/_internal/pub/test/snapshot/upgrades_snapshot_test.dart
copy to sdk/lib/_internal/pub/test/snapshot/updates_snapshot_for_git_dependency_test.dart
index 10aefb6bbb2024f0bb5d5ff1fb0ae97c20eee4c1..c1c1f68d1267989c8755a959ea46a0ff66f3d589 100644
--- a/sdk/lib/_internal/pub/test/snapshot/upgrades_snapshot_test.dart
+++ b/sdk/lib/_internal/pub/test/snapshot/updates_snapshot_for_git_dependency_test.dart
@@ -12,39 +12,41 @@ import '../test_pub.dart';
 
 main() {
   initConfig();
-  integration("upgrades a snapshot when its package is upgraded", () {
-    servePackages((builder) {
-      builder.serve("foo", "1.2.3", contents: [
-        d.dir("bin", [
-          d.file("hello.dart", "void main() => print('hello!');")
-        ])
-      ]);
-    });
+  integration("upgrades a snapshot when a git dependency is upgraded", () {
+    ensureGit();
 
-    d.appDir({"foo": "any"}).create();
+    d.git('foo.git', [
+      d.pubspec({
+        "name": "foo",
+        "version": "0.0.1"
+      }),
+      d.dir("bin", [
+        d.file("hello.dart", "void main() => print('Hello!');")
+      ])
+    ]).create();
+
+    d.appDir({"foo": {"git": "../foo.git"}}).create();
 
     pubGet(output: contains("Precompiled foo:hello."));
 
     d.dir(p.join(appPath, '.pub', 'bin', 'foo'), [
-      d.matcherFile('hello.dart.snapshot', contains('hello!'))
+      d.matcherFile('hello.dart.snapshot', contains('Hello!'))
     ]).validate();
 
-    servePackages((builder) {
-      builder.serve("foo", "1.2.4", contents: [
-        d.dir("bin", [
-          d.file("hello.dart", "void main() => print('hello 2!');")
-        ])
-      ]);
-    });
+    d.git('foo.git', [
+      d.dir("bin", [
+        d.file("hello.dart", "void main() => print('Goodbye!');")
+      ])
+    ]).commit();
 
     pubUpgrade(output: contains("Precompiled foo:hello."));
 
     d.dir(p.join(appPath, '.pub', 'bin', 'foo'), [
-      d.matcherFile('hello.dart.snapshot', contains('hello 2!'))
+      d.matcherFile('hello.dart.snapshot', contains('Goodbye!'))
     ]).validate();
 
     var process = pubRun(args: ['foo:hello']);
-    process.stdout.expect("hello 2!");
+    process.stdout.expect("Goodbye!");
     process.shouldExit();
   });
 }