Kill the process before attempting to drain the streams

The output stream for a process is only closed once the
process has quit. Gosh knows how we managed to get this
to work before, but we now do this.

java/client/src/org/openqa/selenium/os/UnixProcess.java

@@ -42,6 +42,7 @@
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;

class UnixProcess implements OsProcess {
@@ -115,6 +116,19 @@ public int destroy() {
    SeleniumWatchDog watchdog = executeWatchdog;
    watchdog.waitForProcessStarted();

    // I literally have no idea why we don't try and kill the process nicely on Windows. If you do,
    // answers on the back of a postcard to SeleniumHQ, please.
    if (!thisIsWindows()) {
      watchdog.destroyProcess();
      watchdog.waitForTerminationAfterDestroy(2, SECONDS);
    }

    if (isRunning()) {
      watchdog.destroyHarder();
      watchdog.waitForTerminationAfterDestroy(1, SECONDS);
    }

    // Make a best effort to drain the streams.
    if (streamHandler != null) {
      // Stop trying to read the output stream so that we don't race with the stream being closed
      // when the process is destroyed.
@@ -123,20 +137,13 @@ public int destroy() {
        streamHandler.stop();
      } catch (IOException e) {
        // Ignore and destroy the process anyway.
        log.log(
            Level.INFO,
            "Unable to drain process streams. Ignoring but the exception being swallowed follows.",
            e);
      }
    }

    if (!thisIsWindows()) {
      watchdog.destroyProcess();
      watchdog.waitForTerminationAfterDestroy(2, SECONDS);
      if (!isRunning()) {
        return getExitCode();
      }
      log.info("Command failed to close cleanly. Destroying forcefully (v2). " + this);
    }

    watchdog.destroyHarder();
    watchdog.waitForTerminationAfterDestroy(1, SECONDS);
    if (!isRunning()) {
      return getExitCode();
    }