Fixes up batch-mode release of utility process.

When running in single-process mode, e.g. during unit tests, the utility
process cannot terminate the process and instead closes its channel to trigger
cleanup.  Ending batchmode triggers process termination for the multi-process
mode, but does nothing during single-process mode, leading to test timeout.
This can be fixed by adding the single-process mode logic to the EndBatchMode
code path.

BUG=341935

Review URL: https://codereview.chromium.org/157783002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251209 0039d316-1c4b-4281-b951-d872f2087c98

content/utility/utility_thread_impl.cc

@@ -118,7 +118,8 @@ void UtilityThreadImpl::OnBatchModeStarted() {
 }
 
 void UtilityThreadImpl::OnBatchModeFinished() {
-  ChildProcess::current()->ReleaseProcess();
+  batch_mode_ = false;
+  ReleaseProcessIfNeeded();
 }
 
 #if defined(OS_POSIX)