When clearing plugin data at shutdown, wait for it to finish.

chrome/browser/browsing_data_remover.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/browsing_data_remover.h"
 
 #include <map>
 #include <set>
 
 #include "base/callback.h"
@@ skipping 242 matching lines @@
         BrowserThread::IO, FROM_HERE,
         NewRunnableMethod(this, &BrowsingDataRemover::ClearCacheOnIOThread));
   }
 
   if (remove_mask & REMOVE_LSO_DATA) {
     UserMetrics::RecordAction(UserMetricsAction("ClearBrowsingData_LSOData"));
 
     waiting_for_clear_lso_data_ = true;
     if (!plugin_data_remover_.get())
       plugin_data_remover_ = new PluginDataRemover();
-    plugin_data_remover_->StartRemoving(
-        delete_begin_,
-        NewRunnableMethod(this, &BrowsingDataRemover::OnClearedPluginData));
+    base::WaitableEvent* event =
+        plugin_data_remover_->StartRemoving(delete_begin_);
+    watcher_.StartWatching(event, this);
   }
 
   NotifyAndDeleteIfDone();
 }
 
 void BrowsingDataRemover::AddObserver(Observer* observer) {
   observer_list_.AddObserver(observer);
 }
 
 void BrowsingDataRemover::RemoveObserver(Observer* observer) {
@@ skipping 226 matching lines @@
 
 ChromeAppCacheService* BrowsingDataRemover::GetAppCacheService() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   ChromeURLRequestContext* request_context =
       reinterpret_cast<ChromeURLRequestContext*>(
           request_context_getter_->GetURLRequestContext());
   return request_context ? request_context->appcache_service()
                          : NULL;
 }
 
-void BrowsingDataRemover::OnClearedPluginData() {
+void BrowsingDataRemover::OnWaitableEventSignaled(
+    base::WaitableEvent* waitable_event) {
   waiting_for_clear_lso_data_ = false;
   NotifyAndDeleteIfDone();
 }