Gracefully deal with clearing content settings for unregistered extensions.

chrome/browser/extensions/api/content_settings/content_settings_store.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/api/content_settings/content_settings_store.h"
 
 #include <set>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 178 matching lines @@
         return &(i->second->incognito_session_only_settings);
     }
   }
   return NULL;
 }
 
 const OriginIdentifierValueMap* ContentSettingsStore::GetValueMap(
     const std::string& ext_id,
     ExtensionPrefsScope scope) const {
   ExtensionEntryMap::const_iterator i = FindEntry(ext_id);
-  if (i != entries_.end()) {
-    switch (scope) {
-      case kExtensionPrefsScopeRegular:
-        return &(i->second->settings);
-      case kExtensionPrefsScopeIncognitoPersistent:
-        return &(i->second->incognito_persistent_settings);
-      case kExtensionPrefsScopeIncognitoSessionOnly:
-        return &(i->second->incognito_session_only_settings);
-    }
+  if (i == entries_.end())
+    return NULL;
+
+  switch (scope) {
+    case kExtensionPrefsScopeRegular:
+      return &(i->second->settings);
+    case kExtensionPrefsScopeIncognitoPersistent:
+      return &(i->second->incognito_persistent_settings);
+    case kExtensionPrefsScopeIncognitoSessionOnly:
+      return &(i->second->incognito_session_only_settings);
   }
+
+  NOTREACHED();
   return NULL;
 }
 
 void ContentSettingsStore::ClearContentSettingsForExtension(
     const std::string& ext_id,
     ExtensionPrefsScope scope) {
   bool notify = false;
   {
     base::AutoLock lock(lock_);
     OriginIdentifierValueMap* map = GetValueMap(ext_id, scope);
+    if (!map)
+      return;
     notify = !map->empty();
     map->clear();
   }
   if (notify) {
     NotifyOfContentSettingChanged(ext_id, scope != kExtensionPrefsScopeRegular);
   }
 }
 
 base::ListValue* ContentSettingsStore::GetSettingsForExtension(
     const std::string& extension_id,
@@ skipping 120 matching lines @@
 ContentSettingsStore::FindEntry(const std::string& ext_id) const {
   ExtensionEntryMap::const_iterator i;
   for (i = entries_.begin(); i != entries_.end(); ++i) {
     if (i->second->id == ext_id)
       return i;
   }
   return entries_.end();
 }
 
 }  // namespace extensions