Initialize all members of ContextMenuParams in the ctor

content/public/common/context_menu_params.cc

 // Copyright (c) 2011 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 "content/public/common/context_menu_params.h"
 
 namespace content {
 
 const int32 CustomContextMenuContext::kCurrentRenderWidget = kint32max;
 
@@ skipping 14 matching lines @@
       speech_input_enabled(false),
       spellcheck_enabled(false),
       is_editable(false),
       writing_direction_default(
           blink::WebContextMenuData::CheckableMenuItemDisabled),
       writing_direction_left_to_right(
           blink::WebContextMenuData::CheckableMenuItemEnabled),
       writing_direction_right_to_left(
           blink::WebContextMenuData::CheckableMenuItemEnabled),
       edit_flags(0),
-      referrer_policy(blink::WebReferrerPolicyDefault) {
+      referrer_policy(blink::WebReferrerPolicyDefault),
+      source_type(ui::MENU_SOURCE_NONE) {
 }
 
 ContextMenuParams::~ContextMenuParams() {
 }
 
 }  // namespace content