Delete the PreferenceMACs on profile deletion.

chrome/browser/profiles/profile_manager.cc

Index: chrome/browser/profiles/profile_manager.cc
diff --git a/chrome/browser/profiles/profile_manager.cc b/chrome/browser/profiles/profile_manager.cc
index 5f2317b7c992597829e7e6a8f91f739b4878e8ca..599195a7bb8e21869952fe15e9de32a8bfe8c9b1 100644
--- a/chrome/browser/profiles/profile_manager.cc
+++ b/chrome/browser/profiles/profile_manager.cc
@@ -1510,6 +1510,9 @@ void ProfileManager::FinishDeletingProfile(
     // The Profile Data doesn't get wiped until Chrome closes. Since we promised
     // that the user's data would be removed, do so immediately.
     profiles::RemoveBrowsingDataForProfile(profile_dir);
+
+    // Clean-up pref data that won't be cleaned up by NukeProfileFromDisk.
+    profile->GetPrefs()->OnStoreDeletionFromDisk();
   } else {
     // It is safe to delete a not yet loaded Profile from disk.

[gab, 2017/06/06 14:48:26]

The logic will go through here if the user deletes a profile from
chrome://settings without loading it. We need to support that use case too.

[proberge, 2017/06/07 19:22:50]

Done. Note that this involves added complexity to try to load the profile in
order to call OnStoreDeletionFromDisk. Clearing the registry will still fail if
the profile can't be loaded. 

Loading the the profile might be working against the todo for
https://bugs.chromium.org/p/chromium/issues/detail?id=88586.

In practice, I couldn't get this branch to be hit when removing a profile on
Windows. When trying to remove a profile, the UI displays some stats (This will
permanently delete N items from your device.) which require loading the profile.

     BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,