Always destroy CrxInstaller on the UI Thread

chrome/browser/extensions/crx_installer.cc

Index: chrome/browser/extensions/crx_installer.cc
diff --git a/chrome/browser/extensions/crx_installer.cc b/chrome/browser/extensions/crx_installer.cc
index c76a45d332cba783425668b9cc409fd47409a885..65fc12666b3c39295978d075716e03697813180d 100644
--- a/chrome/browser/extensions/crx_installer.cc
+++ b/chrome/browser/extensions/crx_installer.cc
@@ -108,7 +108,9 @@ scoped_refptr<CrxInstaller> CrxInstaller::Create(
 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),
@@ -163,11 +165,8 @@ CrxInstaller::CrxInstaller(base::WeakPtr<ExtensionService> service_weak,
 }
 
 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) {