[Linux] Use PR_SET_NO_NEW_PRIVS by default in base/process/launch.h.

chrome/browser/chrome_main_browsertest.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/test/ui/ui_test.h"
 
 #include "base/command_line.h"
 #include "base/path_service.h"
 #include "base/process/launch.h"
 #include "chrome/browser/chrome_notification_types.h"
@@ skipping 14 matching lines @@
 
 // These tests don't apply to the Mac version; see GetCommandLineForRelaunch
 // for details.
 #if !defined(OS_MACOSX)
 
 class ChromeMainTest : public InProcessBrowserTest {
  public:
   ChromeMainTest() {}
 
   void Relaunch(const CommandLine& new_command_line) {
-    base::LaunchProcess(new_command_line, base::LaunchOptions(), NULL);
+    base::LaunchOptions options;
+#if defined(OS_LINUX)
+    // To prevent accidental privilege sharing to an untrusted child, processes
+    // are started with PR_SET_NO_NEW_PRIVS. Do not set that here, since this
+    // new child will be a test browser process.
+    options.allow_new_privs = true;
+#endif
+    base::LaunchProcess(new_command_line, options, NULL);
   }
 };
 
 // Make sure that the second invocation creates a new window.
 IN_PROC_BROWSER_TEST_F(ChromeMainTest, SecondLaunch) {
 #if defined(OS_WIN) && defined(USE_ASH)
   // Disable this test in Metro+Ash for now (http://crbug.com/262796).
   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kAshBrowserTests))
     return;
 #endif
@@ skipping 101 matching lines @@
         content::NotificationService::AllSources());
   Relaunch(new_command_line);
   tab_observer.Wait();
 
   // There should be one normal and one incognito window now.
   ASSERT_EQ(2u, chrome::GetTotalBrowserCount());
   ASSERT_EQ(1u, chrome::GetTabbedBrowserCount(profile, host_desktop_type));
 }
 
 #endif  // !OS_MACOSX