[Process] Consistently use getProcess() in tests

Author: nicolas-grekas

src/Symfony/Component/Process/Tests/ProcessTest.php

@@ -1181,7 +1181,7 @@ public function pipesCodeProvider()
      * @dataProvider provideVariousIncrementals
      */
     public function testIncrementalOutputDoesNotRequireAnotherCall($stream, $method) {
-        $process = new Process(self::$phpBin.' -r '.escapeshellarg('$n = 0; while ($n < 3) { file_put_contents(\''.$stream.'\', $n, 1); $n++; usleep(1000); }'), null, null, null, null);
+        $process = $this->getProcess(self::$phpBin.' -r '.escapeshellarg('$n = 0; while ($n < 3) { file_put_contents(\''.$stream.'\', $n, 1); $n++; usleep(1000); }'), null, null, null, null);
         $process->start();
         $result = '';
         $limit = microtime(true) + 3;