[Android] Add supportMultipleWindows setting

webkit/glue/webpreferences.h

 // 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.
 //
 // A struct for managing webkit's settings.
 //
 // Adding new values to this class probably involves updating
 // WebKit::WebSettings, content/common/view_messages.h, browser/tab_contents/
 // render_view_host_delegate_helper.cc, and browser/profiles/profile.cc.
 
@@ skipping 104 matching lines @@
   bool accelerated_plugins_enabled;
   bool memory_info_enabled;
   bool fullscreen_enabled;
   bool allow_displaying_insecure_content;
   bool allow_running_insecure_content;
 #if defined(OS_ANDROID)
   bool text_autosizing_enabled;
   float font_scale_factor;
   bool force_enable_zoom;
   bool user_gesture_required_for_media_playback;
+  bool supports_multiple_windows;
 #endif
   bool password_echo_enabled;
   bool should_print_backgrounds;
   bool enable_scroll_animator;
   bool visual_word_movement_enabled;
   bool css_sticky_position_enabled;
   bool css_regions_enabled;
   bool css_shaders_enabled;
   bool css_variables_enabled;
   bool device_supports_touch;
@@ skipping 20 matching lines @@
   // the embedder to use the same default value.
   WebPreferences();
   ~WebPreferences();
 
   void Apply(WebKit::WebView* web_view) const;
 };
 
 }  // namespace webkit_glue
 
 #endif  // WEBKIT_GLUE_WEBPREFERENCES_H__