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

apps/load_and_launch_browsertest.cc

Index: apps/load_and_launch_browsertest.cc
diff --git a/apps/load_and_launch_browsertest.cc b/apps/load_and_launch_browsertest.cc
index fecfe844f1465afcf4d45a653e069875495da995..6cc484aba5feccadce5f7750bec2e138a0d623f8 100644
--- a/apps/load_and_launch_browsertest.cc
+++ b/apps/load_and_launch_browsertest.cc
@@ -50,8 +50,15 @@ IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest,
                                  app_path.value());
 
   new_cmdline.AppendSwitch(content::kLaunchAsBrowser);
+  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::ProcessHandle process;
-  base::LaunchProcess(new_cmdline, base::LaunchOptions(), &process);
+  base::LaunchProcess(new_cmdline, options, &process);
   ASSERT_NE(base::kNullProcessHandle, process);
 
   ASSERT_TRUE(launched_listener.WaitUntilSatisfied());
@@ -93,8 +100,15 @@ IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest,
   new_cmdline.AppendSwitch(content::kLaunchAsBrowser);
   new_cmdline.AppendArgPath(test_file_path);
 
+  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::ProcessHandle process;
-  base::LaunchProcess(new_cmdline, base::LaunchOptions(), &process);
+  base::LaunchProcess(new_cmdline, options, &process);
   ASSERT_NE(base::kNullProcessHandle, process);
 
   ASSERT_TRUE(launched_listener.WaitUntilSatisfied());