Validate and report peer's PID to WorkerProcessIpcDelegate so it will be able to duplicate handles to and from the worker process.

As a side effect WorkerProcessLauncher::Delegate is now responsible for retrieving the client's PID and deciding whether a launch failed due to a permanent error condition.

BUG=134694


Review URL: https://chromiumcodereview.appspot.com/11143025

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@162778 0039d316-1c4b-4281-b951-d872f2087c98
DaemonProcessTest::~DaemonProcessTest() {
}

DaemonProcessTest::~DaemonProcessTest() {
}
