Ensure tests check the return of SpawnChild() when they may wait without timeouts

content/common/sandbox_mac_diraccess_unittest.mm

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import <Cocoa/Cocoa.h>
 #include <dirent.h>
 
 extern "C" {
 #include <sandbox.h>
 }
@@ skipping 17 matching lines @@
 // Tests need to be in the same namespace as the sandbox::Sandbox class to be
 // useable with FRIEND_TEST() declaration.
 namespace sandbox {
 
 class MacDirAccessSandboxTest : public base::MultiProcessTest {
  public:
   bool CheckSandbox(const std::string& directory_to_try) {
     setenv(kSandboxAccessPathKey, directory_to_try.c_str(), 1);
     base::ProcessHandle child_process = SpawnChild("mac_sandbox_path_access",
                                                    false);
+    if (child_process == base::kNullProcessHandle) {
+      LOG(WARNING) << "SpawnChild failed";
+      return false;
+    }
     int code = -1;
     if (!base::WaitForExitCode(child_process, &code)) {
       LOG(WARNING) << "base::WaitForExitCode failed";
       return false;
     }
     return code == 0;
   }
 };
 
 TEST_F(MacDirAccessSandboxTest, StringEscape) {
@@ skipping 247 matching lines @@
     PLOG(ERROR) << "Sandbox breach: was able to write ("
                 << denied_file2.value()
                 << ")";
     return -1;
   }
 
   return 0;
 }
 
 }  // namespace sandbox