Don't clear existing extension-defined preferences and content settings when reloading or updating…

chrome/browser/extensions/extension_pref_value_map.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/extension_pref_value_map.h"
 
 #include "base/prefs/pref_value_map.h"
 #include "base/stl_util.h"
 #include "base/values.h"
 
@@ skipping 95 matching lines @@
     const std::string& pref_key,
     bool* from_incognito) const {
   bool incognito = (from_incognito != NULL);
   ExtensionEntryMap::const_iterator winner =
       GetEffectivePrefValueController(pref_key, incognito, from_incognito);
   if (winner == entries_.end())
     return false;
   return winner->first == extension_id;
 }
 
 void ExtensionPrefValueMap::RegisterExtension(const std::string& ext_id,

[Jeffrey Yasskin, 2013/09/06 21:31:56]

This is called from PreferenceAPI::InitExtensionControlledPrefs() and
ExtensionPrefs::FinishExtensionInfoPrefs(). Is the new behavior what we want in
both places?

[Bernhard Bauer, 2013/09/09 21:02:03]

Yes, PreferenceAPI::InitExtensionControlledPrefs() is called during startup,
where the map should be empty anyway.

                                               const base::Time& install_time,
                                               bool is_enabled) {
   if (entries_.find(ext_id) != entries_.end())
-    UnregisterExtension(ext_id);
+    return;
+
   entries_[ext_id] = new ExtensionEntry;
   entries_[ext_id]->install_time = install_time;

[Jeffrey Yasskin, 2013/09/06 21:31:56]

Using the older install time is probably right in either case. An extension
upgrade probably shouldn't change the users effective preferences.

   entries_[ext_id]->enabled = is_enabled;

[Jeffrey Yasskin, 2013/09/06 21:31:56]

When we re-install an extension, it seems like we'd want to update the enabled
state, unless we're somehow guaranteed that it'll already be up to date. Add a
DCHECK if the second is true?

[Bernhard Bauer, 2013/09/09 21:02:03]

What do you mean by up to date?

[Jeffrey Yasskin, 2013/09/09 21:15:28]

Say the extension is disabled, but RegisterExtension() is called with
is_enabled==true. That's what I mean by entries_[ext_id]->enabled being "not up
to date". Now, I think that's impossible because is_enabled is read out of
entries_[ext_id] in these cases, but a DCHECK would make sure that doesn't get
broken in the future.

[Bernhard Bauer, 2013/09/09 21:31:46]

Gotcha. Yes, that makes sense.

 }
 
 void ExtensionPrefValueMap::UnregisterExtension(const std::string& ext_id) {
   ExtensionEntryMap::iterator i = entries_.find(ext_id);
   if (i == entries_.end())
     return;
   std::set<std::string> keys;  // keys set by this extension
   GetExtensionControlledKeys(*(i->second), &keys);
 
   delete i->second;
@@ skipping 221 matching lines @@
 
 void ExtensionPrefValueMap::NotifyPrefValueChanged(const std::string& key) {
   FOR_EACH_OBSERVER(ExtensionPrefValueMap::Observer, observers_,
                     OnPrefValueChanged(key));
 }
 
 void ExtensionPrefValueMap::NotifyOfDestruction() {
   FOR_EACH_OBSERVER(ExtensionPrefValueMap::Observer, observers_,
                     OnExtensionPrefValueMapDestruction());
 }