Forcibly clear worker ref counts on shutdown.

content/browser/browser_context.cc

 // Copyright (c) 2012 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 "content/public/browser/browser_context.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <algorithm>
 #include <limits>
@@ skipping 11 matching lines @@
 #include "content/browser/blob_storage/chrome_blob_storage_context.h"
 #include "content/browser/download/download_manager_impl.h"
 #include "content/browser/indexed_db/indexed_db_context_impl.h"
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
 #include "content/browser/push_messaging/push_messaging_router.h"
 #include "content/browser/storage_partition_impl_map.h"
 #include "content/common/child_process_host_impl.h"
 #include "content/public/browser/blob_handle.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
+#include "content/public/browser/render_process_host.h"
 #include "content/public/browser/site_instance.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/mojo_shell_connection.h"
 #include "content/public/common/service_names.h"
 #include "net/cookies/cookie_store.h"
 #include "net/ssl/channel_id_service.h"
 #include "net/ssl/channel_id_store.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "services/file/file_service.h"
@@ skipping 283 matching lines @@
                                       callback);
 }
 
 // static
 void BrowserContext::NotifyWillBeDestroyed(BrowserContext* browser_context) {
   // Service Workers must shutdown before the browser context is destroyed,
   // since they keep render process hosts alive and the codebase assumes that
   // render process hosts die before their profile (browser context) dies.
   ForEachStoragePartition(browser_context,
                           base::Bind(ShutdownServiceWorkerContext));
+
+  // Some tests don't setup RenderProcessHost and don't necessarily run
+  // on the UI thread anyway, so we can't use the AllHostIterator.

[jam, 2016/09/14 17:10:49]

how many tests is this for? can't we just add testbundles to them so that we
avoid adding this to production code? it is a mistake for this to be called on
non-UI thread for production code, so this statement can mask other bugs.

[falken, 2016/09/21 08:59:43]

Done, removed this and added testbundles.

+  if (!BrowserThread::CurrentlyOn(BrowserThread::UI))
+    return;
+
+  // Shared workers also keep render process hosts alive. However shared worker
+  // bookkeeping is done on the IO thread and we want to ensure the hosts are
+  // destructed now, so forcibly release their ref counts.
+  for (content::RenderProcessHost::iterator host_iterator =

[jam, 2016/09/14 17:10:49]

here and below, no "content::"

[falken, 2016/09/21 08:59:43]

Done.

+           content::RenderProcessHost::AllHostsIterator();
+       !host_iterator.IsAtEnd(); host_iterator.Advance()) {
+    content::RenderProcessHost* host = host_iterator.GetCurrentValue();
+    if (host->GetBrowserContext() == browser_context)
+      host->ForceReleaseWorkerRefCounts();
+  }
 }
 
 void BrowserContext::EnsureResourceContextInitialized(BrowserContext* context) {
   // This will be enough to tickle initialization of BrowserContext if
   // necessary, which initializes ResourceContext. The reason we don't call
   // ResourceContext::InitializeResourceContext() directly here is that
   // ResourceContext initialization may call back into BrowserContext
   // and when that call returns it'll end rewriting its UserData map. It will
   // end up rewriting the same value but this still causes a race condition.
   //
@@ skipping 154 matching lines @@
   if (GetUserData(kDownloadManagerKeyName))
     GetDownloadManager(this)->Shutdown();
 }
 
 void BrowserContext::ShutdownStoragePartitions() {
   if (GetUserData(kStoragePartitionMapKeyName))
     RemoveUserData(kStoragePartitionMapKeyName);
 }
 
 }  // namespace content