Run dartfmt on all files under runtime.

runtime/observatory/tests/service/get_retaining_path_rpc_test.dart

Index: runtime/observatory/tests/service/get_retaining_path_rpc_test.dart
diff --git a/runtime/observatory/tests/service/get_retaining_path_rpc_test.dart b/runtime/observatory/tests/service/get_retaining_path_rpc_test.dart
index c2b7fc1cfbcd2784e69034ec452b4d2ce1c78bbf..aa0c3289780aef53b31b5e630901e312c4f17f3e 100644
--- a/runtime/observatory/tests/service/get_retaining_path_rpc_test.dart
+++ b/runtime/observatory/tests/service/get_retaining_path_rpc_test.dart
@@ -62,12 +62,12 @@ var tests = [
     bool caughtException;
     try {
       await isolate.invokeRpcNoUpgrade('_getRetainingPath', params);
-      expect(false, isTrue, reason:'Unreachable');
+      expect(false, isTrue, reason: 'Unreachable');
     } on ServerRpcException catch (e) {
       caughtException = true;
       expect(e.code, equals(ServerRpcException.kInvalidParams));
       expect(e.data['details'],
-             "_getRetainingPath expects the \'limit\' parameter");
+          "_getRetainingPath expects the \'limit\' parameter");
     }
     expect(caughtException, isTrue);
   },
@@ -124,8 +124,8 @@ var tests = [
     var result = await isolate.invokeRpcNoUpgrade('_getRetainingPath', params);
     expect(result['type'], equals('RetainingPath'));
     expect(result['elements'].length, equals(3));
-    expect(result['elements'][1]['parentMapKey']['valueAsString'],
-        equals('key'));
+    expect(
+        result['elements'][1]['parentMapKey']['valueAsString'], equals('key'));
     expect(result['elements'][2]['value']['name'], equals('globalMap1'));
   },
 
@@ -140,9 +140,9 @@ var tests = [
     expect(result['type'], equals('RetainingPath'));
     expect(result['elements'].length, equals(3));
     expect(result['elements'][1]['parentMapKey']['class']['name'],
-      equals('_TestClass'));
+        equals('_TestClass'));
     expect(result['elements'][2]['value']['name'], equals('globalMap2'));
   }
 ];
 
-main(args) async => runIsolateTests(args, tests, testeeBefore:warmup);
+main(args) async => runIsolateTests(args, tests, testeeBefore: warmup);