Revert of Fix SharedWorker leak when script load has failed....

Revert of Fix SharedWorker leak when script load has failed. (https://codereview.chromium.org/424653002/)

Reason for revert:
May cause crash

Original issue's description:
> Fix SharedWorker leak when script load has failed.
> 
> When SharedWorker script load has failed and the |WebSharedWorkerImpl|
> was explicit told to terminate, the |WebSharedWorkerImpl| instance
> was never deleted.
> 
> This CL fixes the issue by invoking "delete this" when a worker thread
> instance does not exist in |stopWorkerThread()|.
> 
> TEST=fast/workers/worker-crash-with-invalid-location.html doesn't leak when --enable-leak-detection
> BUG=364390
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=179011

TBR=falken@chromium.org,tkent@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=364390

Review URL: https://codereview.chromium.org/424923002

git-svn-id: svn://svn.chromium.org/blink/trunk@179088 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/web/WebSharedWorkerImpl.cpp

@@ -178,23 +178,12 @@ void WebSharedWorkerImpl::stopWorkerThread()
     if (m_askedToTerminate)
         return;
     m_askedToTerminate = true;
-
-    bool hasPendingActivity = false;
     if (m_mainScriptLoader) {
         m_mainScriptLoader->cancel();
         m_mainScriptLoader.clear();
-        hasPendingActivity = true;
     }
-    if (m_workerThread) {
+    if (m_workerThread)
         m_workerThread->stop();
-        hasPendingActivity = true;
-    }
-
-    if (!hasPendingActivity) {
-        // If there are no active WorkerThread, |workerGlobalScopeClosed()|
-        // callback to delete this is never called, so we should clean up here.
-        delete this;
-    }
 }
 
 void WebSharedWorkerImpl::initializeLoader(const WebURL& url)