Added Protector backup for Preferences.

chrome/browser/extensions/extension_prefs.cc

Index: chrome/browser/extensions/extension_prefs.cc
diff --git a/chrome/browser/extensions/extension_prefs.cc b/chrome/browser/extensions/extension_prefs.cc
index 890ba9970794457cd678d4eed6094c107e240ac9..68070c68ad3bf1a61d22a58b1313940ca46a1520 100644
--- a/chrome/browser/extensions/extension_prefs.cc
+++ b/chrome/browser/extensions/extension_prefs.cc
@@ -1543,6 +1543,23 @@ void ExtensionPrefs::GetExtensions(ExtensionIdSet* out) {
   }
 }
 
+// static
+void ExtensionPrefs::GetExtensionsFrom(
+    const base::DictionaryValue* extension_prefs,
+    ExtensionIdSet* out) {
+  CHECK(out);
+  for (base::DictionaryValue::key_iterator it = extension_prefs->begin_keys();
+       it != extension_prefs->end_keys(); ++it) {
+    DictionaryValue* ext;
+    if (!extension_prefs->GetDictionaryWithoutPathExpansion(*it, &ext)) {
+      NOTREACHED() << "Invalid pref for extension " << *it;
+      continue;
+    }
+    if (!IsBlacklistBitSet(ext))
+      out->push_back(*it);
+  }
+}
+
 void ExtensionPrefs::FixMissingPrefs(const ExtensionIdSet& extension_ids) {
   // Fix old entries that did not get an installation time entry when they
   // were installed or don't have a preferences field.