Always destroy CrxInstaller on the UI Thread

extensions/browser/sandboxed_unpacker.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 "extensions/browser/sandboxed_unpacker.h"
 
 #include <set>
 
 #include "base/base64.h"
 #include "base/bind.h"
@@ skipping 194 matching lines @@
   if (!base::ReadFileToString(path, &file_str))
     return false;
 
   IPC::Message pickle(file_str.data(), file_str.size());
   PickleIterator iter(pickle);
   return IPC::ReadParam(&pickle, &iter, catalogs);
 }
 
 }  // namespace
 
+SandboxedUnpackerClient::SandboxedUnpackerClient(
+    const scoped_refptr<base::MessageLoopProxy>& loop)
+    : RefCountedDeleteOnMessageLoop<SandboxedUnpackerClient>(loop) {

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

Can you put BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI)
straight in here instead of plumbing it up from all subclasses?

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

Done. Turns out //extensions/browser is fine wrt DEPS. But at least this forced
me to double-check all the derived classes to ensure they're OK with the change.

Added a DCHECK_CURRENTLY_ON(BrowserThread::UI); to the constructor here, and
updated the header comment.

+}
+
 SandboxedUnpacker::SandboxedUnpacker(
     const CRXFileInfo& file,
     Manifest::Location location,
     int creation_flags,
     const base::FilePath& extensions_dir,
     const scoped_refptr<base::SequencedTaskRunner>& unpacker_io_task_runner,
     SandboxedUnpackerClient* client)
     : crx_path_(file.path),
       package_hash_(base::StringToLowerASCII(file.expected_hash)),
       check_crx_hash_(false),
@@ skipping 618 matching lines @@
 
 void SandboxedUnpacker::Cleanup() {
   DCHECK(unpacker_io_task_runner_->RunsTasksOnCurrentThread());
   if (!temp_dir_.Delete()) {
     LOG(WARNING) << "Can not delete temp directory at "
                  << temp_dir_.path().value();
   }
 }
 
 }  // namespace extensions