Always destroy CrxInstaller on the UI Thread

chrome/browser/extensions/crx_installer.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 "chrome/browser/extensions/crx_installer.h"
 
 #include <map>
 #include <set>
 
 #include "base/bind.h"
@@ skipping 90 matching lines @@
 scoped_refptr<CrxInstaller> CrxInstaller::Create(
     ExtensionService* service,
     scoped_ptr<ExtensionInstallPrompt> client,
     const WebstoreInstaller::Approval* approval) {
   return new CrxInstaller(service->AsWeakPtr(), client.Pass(), approval);
 }
 
 CrxInstaller::CrxInstaller(base::WeakPtr<ExtensionService> service_weak,
                            scoped_ptr<ExtensionInstallPrompt> client,
                            const WebstoreInstaller::Approval* approval)
-    : install_directory_(service_weak->install_directory()),
+    : SandboxedUnpackerClient(
+          BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI)),
+      install_directory_(service_weak->install_directory()),
       install_source_(Manifest::INTERNAL),
       approved_(false),
       hash_check_failed_(false),
       expected_manifest_check_level_(
           WebstoreInstaller::MANIFEST_CHECK_LEVEL_STRICT),
       expected_version_strict_checking_(false),
       extensions_enabled_(service_weak->extensions_enabled()),
       delete_source_(false),
       create_app_shortcut_(false),
       service_weak_(service_weak),
@@ skipping 34 matching lines @@
   if (approval->minimum_version.get()) {
     expected_version_.reset(new Version(*approval->minimum_version));
     expected_version_strict_checking_ = false;
   }
 
   show_dialog_callback_ = approval->show_dialog_callback;
   set_is_ephemeral(approval->is_ephemeral);
 }
 
 CrxInstaller::~CrxInstaller() {
-  // Make sure the UI is deleted on the ui thread.
-  if (client_) {
-    BrowserThread::DeleteSoon(BrowserThread::UI, FROM_HERE, client_);
-    client_ = NULL;
-  }
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  // The scoped_ptr |client_| data member must be destroyed on the UI thread.

[benwells, 2015/04/14 22:14:19]

Nit: the client_ member was destroyed on the ui thread before. maybe add a
comment explaining why that alone is not enough.

[tapted, 2015/04/15 03:07:44]

Done.

 }
 
 void CrxInstaller::InstallCrx(const base::FilePath& source_file) {
   InstallCrxFile(CRXFileInfo(source_file));
 }
 
 void CrxInstaller::InstallCrxFile(const CRXFileInfo& source_file) {
   ExtensionService* service = service_weak_.get();
   if (!service || service->browser_terminating())
     return;
@@ skipping 727 matching lines @@
   if (!prefs->DidExtensionEscalatePermissions(extension()->id()))
     return;
 
   if (client_) {
     AddRef();  // Balanced in InstallUIProceed() and InstallUIAbort().
     client_->ConfirmReEnable(this, extension());
   }
 }
 
 }  // namespace extensions