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

chrome/browser/extensions/extension_pref_value_map.cc

Index: chrome/browser/extensions/extension_pref_value_map.cc
diff --git a/chrome/browser/extensions/extension_pref_value_map.cc b/chrome/browser/extensions/extension_pref_value_map.cc
index c497e5ad1cb65d29cb1dee8bdf09f1c1094fe1e1..bbbe3850b13f28be4cdb6d267abd158d6c9260cf 100644
--- a/chrome/browser/extensions/extension_pref_value_map.cc
+++ b/chrome/browser/extensions/extension_pref_value_map.cc
@@ -117,7 +117,8 @@ void ExtensionPrefValueMap::RegisterExtension(const std::string& ext_id,
                                               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.