Fix DevFS on Android devices

runtime/observatory/tests/service/test_helper.dart

Index: runtime/observatory/tests/service/test_helper.dart
diff --git a/runtime/observatory/tests/service/test_helper.dart b/runtime/observatory/tests/service/test_helper.dart
index 0e8b6e932af424b757e26dcf039252d1c5dd47f0..1a66047744b07f4c4d465c7f5891d0a0b17ea9d8 100644
--- a/runtime/observatory/tests/service/test_helper.dart
+++ b/runtime/observatory/tests/service/test_helper.dart
@@ -255,6 +255,63 @@ class _ServiceTesteeLauncher {
   }
 }
 
+// A tester runner that doesn't spawn a process but instead connects to
+// an already running flutter application running on a device. Assumes
+// port 8100. This is only useful for debugging.
+class _FlutterDeviceServiceTesterRunner {
+  void run({List<String> mainArgs,
+            List<VMTest> vmTests,
+            List<IsolateTest> isolateTests,
+            bool pause_on_start: false,
+            bool pause_on_exit: false,
+            bool trace_service: false,
+            bool trace_compiler: false,
+            bool verbose_vm: false,
+            bool pause_on_unhandled_exceptions: false}) {
+    var port = 8100;
+    serviceWebsocketAddress = 'ws://localhost:$port/ws';
+    serviceHttpAddress = 'http://localhost:$port';
+    var name = Platform.script.pathSegments.last;
+    runZoned(() async {
+      var vm =
+          new WebSocketVM(new WebSocketVMTarget(serviceWebsocketAddress));
+      print('Loading VM...');
+      await vm.load();
+      print('Done loading VM');
+
+      // Run vm tests.
+      if (vmTests != null) {
+        var testIndex = 1;
+        var totalTests = vmTests.length;
+        for (var test in vmTests) {
+          vm.verbose = verbose_vm;
+          print('Running $name [$testIndex/$totalTests]');
+          testIndex++;
+          await test(vm);
+        }
+      }
+
+      // Run isolate tests.
+      if (isolateTests != null) {
+        var isolate = await vm.isolates.first.load();
+        var testIndex = 1;
+        var totalTests = isolateTests.length;
+        for (var test in isolateTests) {
+          vm.verbose = verbose_vm;
+          print('Running $name [$testIndex/$totalTests]');
+          testIndex++;
+          await test(isolate);
+        }
+      }
+    }, onError: (e, st) {
+        if (!_isWebSocketDisconnect(e)) {
+          print('Unexpected exception in service tests: $e $st');
+          throw e;
+        }
+    });
+  }
+}
+
 class _ServiceTesterRunner {
   void run({List<String> mainArgs,
             List<VMTest> vmTests,