Avoid a crash in ProfileManager::GetLastUsedProfileAllowedByPolicy()

chrome/browser/media/tab_desktop_media_list.cc

 // Copyright 2016 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/media/tab_desktop_media_list.h"
 
 #include "base/hash.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/browser.h"
@@ skipping 55 matching lines @@
   thumbnail_task_runner_ =
       worker_pool->GetSequencedTaskRunner(worker_pool->GetSequenceToken());
 }
 
 TabDesktopMediaList::~TabDesktopMediaList() {}
 
 void TabDesktopMediaList::Refresh() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   Profile* profile = ProfileManager::GetLastUsedProfileAllowedByPolicy();
+  if (!profile)
+    return;

[Sergey Ulanov, 2016/08/20 01:08:48]

I think ScheduleNextRefresh still need to be posted in this case. You can just
call here directly:
 if (!profile) {
   ScheduleNextRefresh();
   return;
 }

Looking at this code again I'm not sure GetLastUsedProfileAllowedByPolicy() is
the right thing to do here. It's probably better to pass Profile in the
constructor and use it here.

[afakhry, 2016/08/20 01:33:52]

Done.
This comment should probably be handled as a refactor in a separate CL. For now
let's keep this to fixing the crash.

+
   std::vector<Browser*> browsers;
   for (auto* browser : *BrowserList::GetInstance()) {
     if (browser->profile()->GetOriginalProfile() ==
         profile->GetOriginalProfile()) {
       browsers.push_back(browser);
     }
   }
 
   ImageHashesMap new_favicon_hashes;
   std::vector<SourceDescription> sources;
@@ skipping 37 matching lines @@
           (favicon_hashes_[media_id] != new_favicon_hashes[media_id])) {
         gfx::ImageSkia image = favicon.AsImageSkia();
         image.MakeThreadSafe();
         favicon_pairs.push_back(std::make_pair(media_id, image));
       }
     }
   }
   favicon_hashes_ = new_favicon_hashes;
 
   // Sort tab sources by time. Most recent one first. Then update sources list.
-  for (auto it = tab_map.rbegin(); it != tab_map.rend(); ++it) {
+  for (auto it = tab_map.rbegin(); it != tab_map.rend(); ++it)
     sources.push_back(it->second);
-  }
+
   UpdateSourcesList(sources);
 
   for (const auto& it : favicon_pairs) {
     // Create a thumbail in a different thread and update the thumbnail in
     // current thread.
     base::PostTaskAndReplyWithResult(
         thumbnail_task_runner_.get(), FROM_HERE,
         base::Bind(&CreateEnclosedFaviconImage, thumbnail_size_, it.second),
         base::Bind(&TabDesktopMediaList::UpdateSourceThumbnail,
                    weak_factory_.GetWeakPtr(), it.first));
   }
 
   // ScheduleNextRefresh() needs to be called after all calls for
   // UpdateSourceThumbnail() have done. Therefore, a DoNothing task is posted
   // to the same sequenced task runner that CreateEnlargedFaviconImag()
   // is posted.
   thumbnail_task_runner_.get()->PostTaskAndReply(
       FROM_HERE, base::Bind(&base::DoNothing),
       base::Bind(&TabDesktopMediaList::ScheduleNextRefresh,
                  weak_factory_.GetWeakPtr()));
 }