Add unittest that sandbox::PolicyBase outlives child process.

BUG=663019
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win10_chromium_x64_rel_ng

Review-Url: https://codereview.chromium.org/2513163002
Cr-Commit-Position: refs/heads/master@{#434778}

sandbox/win/src/policy_target_test.cc

@@ -214,6 +214,15 @@ TEST(PolicyTargetTest, OpenProcess) {
       "Opens a process";
 }
 
+TEST(PolicyTargetTest, PolicyBaseNoJobLifetime) {
+  TestRunner runner(JOB_NONE, USER_RESTRICTED_SAME_ACCESS, USER_LOCKDOWN);
+  runner.SetReleasePolicyInRun(true);
+  // TargetPolicy and its SharedMemIPCServer should continue to exist until
+  // the child process dies.
+  EXPECT_EQ(SBOX_TEST_SUCCEEDED, runner.RunTest(L"PolicyTargetTest_thread"))
+      << "Opens the current thread";
+}
+
 // Launches the app in the sandbox and ask it to wait in an
 // infinite loop. Waits for 2 seconds and then check if the
 // desktop associated with the app thread is not the same as the

sandbox/win/tests/common/controller.cc

@@ -242,6 +242,10 @@ int TestRunner::InternalRunTest(const wchar_t* command) {
     result = broker_->SpawnTarget(prog_name, arguments.c_str(), policy_,
                                   &warning_result, &last_error, &target);
   }
+  if (release_policy_in_run_) {
+    policy_->Release();
+    policy_ = nullptr;
+  }
 
   if (SBOX_ALL_OK != result)
     return SBOX_TEST_FAILED_TO_RUN_TEST;

sandbox/win/tests/common/controller.h

@@ -116,6 +116,10 @@ class TestRunner {
   // destroyed.
   void SetKillOnDestruction(bool value) { kill_on_destruction_ = value; }
 
+  // Sets whether the TargetPolicy should be released after the child process
+  // is launched while the test is running.
+  void SetReleasePolicyInRun(bool value) { release_policy_in_run_ = value; }
+
   // Returns the pointers to the policy object. It can be used to modify
   // the policy manually.
   TargetPolicy* GetPolicy();
@@ -147,6 +151,7 @@ class TestRunner {
   bool no_sandbox_;
   bool disable_csrss_;
   bool kill_on_destruction_;
+  bool release_policy_in_run_ = false;
   base::win::ScopedHandle target_process_;
   DWORD target_process_id_;
 };