Reinstate evil hack to suppress permission warnings for searchProvider

extensions/common/permissions/settings_override_permission.cc

 // Copyright 2014 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 "extensions/common/permissions/settings_override_permission.h"
 
 #include <memory>
 
 #include "base/memory/ptr_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 33 matching lines @@
 bool SettingsOverrideAPIPermission::Equal(const APIPermission* rhs) const {
   if (this != rhs)
     CHECK_EQ(info(), rhs->info());
   return true;
 }
 
 bool SettingsOverrideAPIPermission::FromValue(
     const base::Value* value,
     std::string* /*error*/,
     std::vector<std::string>* unhandled_permissions) {
-  return value && value->GetAsString(&setting_value_);
+  // Ugly hack: |value| being null should be an error. But before M46 beta, we
+  // didn't store the parameter for settings override permissions in prefs.
+  // See crbug.com/533086 and crbug.com/619759.
+  // TODO(treib,devlin): Remove this for M56, when hopefully all users will have
+  // updated prefs.
+  // This should read:
+  // return value && value->GetAsString(&setting_value_);
+  return !value || value->GetAsString(&setting_value_);
 }
 
 std::unique_ptr<base::Value> SettingsOverrideAPIPermission::ToValue() const {
   return base::WrapUnique(new base::StringValue(setting_value_));
 }
 
 APIPermission* SettingsOverrideAPIPermission::Clone() const {
   return new SettingsOverrideAPIPermission(info(), setting_value_);
 }
 
@@ skipping 22 matching lines @@
 bool SettingsOverrideAPIPermission::Read(const base::Pickle* m,
                                          base::PickleIterator* iter) {
   return true;
 }
 
 void SettingsOverrideAPIPermission::Log(std::string* log) const {
   *log = setting_value_;
 }
 
 }  // namespace extensions