Synchronize the parent and child processes during launch, ensuring that the

child doesn't try to check in with the Mach broker before the parent is ready.
This resolves a race between the browser and its child processes.

base::LaunchOptions gets a new member, synchronize, currently Mac-only
although there's nothing Mac-specific about the implementation. When set,
it allows base::LaunchProcess clients to request that the child process block
until released by the new base::LaunchSynchronize call. When creating child
processes, the child process launcher now requests this new synchronization
behavior to give it a chance to set up the Mach broker to expect the child
before the child tries to check in with it.

BUG=94295
TEST=Chrome should work. You see fewer of this logged:
     Unknown process (pid) is sending Mach IPC messages!
     But you still might see some of these due to bug 94543.
Review URL: http://codereview.chromium.org/7740036

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@99245 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 4 insertions, 0 deletions

diff --git a/base/process_util_unittest.cc b/base/process_util_unittest.cc
index bcc1308..0403d7a 100644
--- a/base/process_util_unittest.cc
+++ b/base/process_util_unittest.cc
@@ -538,7 +538,11 @@ std::string TestLaunchProcess(const base::environment_vector& env_changes,
   options.wait = true;
   options.environ = &env_changes;
   options.fds_to_remap = &fds_to_remap;
+#if defined(OS_LINUX)
   options.clone_flags = clone_flags;
+#else
+  CHECK_EQ(0, clone_flags);
+#endif  // OS_LINUX
   EXPECT_TRUE(base::LaunchProcess(args, options, NULL));
   PCHECK(HANDLE_EINTR(close(fds[1])) == 0);