Gardening: Mark io/http_basic_test slow. Add debug prints into io/process_start_exception_test.

tests/standalone/io/process_start_exception_test.dart

 // Copyright (c) 2012, 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.
 //
 // Process test program to errors during startup of the process.
 
 import "package:expect/expect.dart";
 import 'dart:async';
 import 'dart:io';
 
+// Constants from errno.h
+const ENOENT = 2;
+const EACCES = 13;
+
+// TODO(http://dartbug.com/28299) This code is added in attempt to collect more
+// information about the flakyness this test experiences on Android bots:
+// sometimes the test fails because we get EACCES instead of ENOENT error
+// from the OS.
+checkForAccessError(error) {
+  if (error.errorCode == EACCES) {
+    report(obj) {
+      final stat = obj.statSync();
+      print("${obj} | ${stat.type} | ${stat.modeString()}");
+    }
+
+    report(Directory.current);
+    report(new File("__path_to_something_that_should_not_exist__"));
+  }
+}
+
 testStartError() {
   Future<Process> processFuture =
       Process.start("__path_to_something_that_should_not_exist__",
                     const []);
   processFuture.then((p) => Expect.fail('got process despite start error'))
   .catchError((error) {
     Expect.isTrue(error is ProcessException);
-    Expect.equals(2, error.errorCode, error.toString());
+    checkForAccessError(error);
+    Expect.equals(ENOENT, error.errorCode, error.toString());
   });
 }
 
 testRunError() {
   Future<ProcessResult> processFuture =
       Process.run("__path_to_something_that_should_not_exist__",
                   const []);
 
   processFuture.then((result) => Expect.fail("exit handler called"))
   .catchError((error) {
     Expect.isTrue(error is ProcessException);
-    Expect.equals(2, error.errorCode, error.toString());
+    checkForAccessError(error);
+    Expect.equals(ENOENT, error.errorCode, error.toString());
   });
 }
 
 main() {
   testStartError();
   testRunError();
 }