Add a policy to re-enable deprecated web platform features.

webkit/common/webpreferences.h

 // Copyright 2013 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
 // blink::WebSettings, content/common/view_messages.h, browser/tab_contents/
 // render_view_host_delegate_helper.cc, and browser/profiles/profile.cc.
 
@@ skipping 24 matching lines @@
     WebInspectorPreferences;
 
 enum EditingBehavior {
   EDITING_BEHAVIOR_MAC,
   EDITING_BEHAVIOR_WIN,
   EDITING_BEHAVIOR_UNIX,
   EDITING_BEHAVIOR_ANDROID,
   EDITING_BEHAVIOR_LAST = EDITING_BEHAVIOR_ANDROID
 };
 
+// Enum of features that can be re-enabled via WebPreferences.
+enum DeprecatedFeature {
+  DEPRECATED_FEATURE_SHOW_MODAL_DIALOG,
+  DEPRECATED_FEATURE_COUNT,
+};
+
 
 // The ISO 15924 script code for undetermined script aka Common. It's the
 // default used on WebKit's side to get/set a font setting when no script is
 // specified.
 WEBKIT_COMMON_EXPORT extern const char kCommonScript[];
 
 }  // namespace webkit_glue
 
 struct WEBKIT_COMMON_EXPORT WebPreferences {
   webkit_glue::ScriptFontFamilyMap standard_font_family_map;
@@ skipping 99 matching lines @@
   // only controls whether or not the "document.cookie" field is properly
   // connected to the backing store, for instance if you wanted to be able to
   // define custom getters and setters from within a unique security content
   // without raising a DOM security exception.
   bool cookie_enabled;
 
   // This flag indicates whether H/W accelerated video decode is enabled for
   // pepper plugins. Defaults to false.
   bool pepper_accelerated_video_decode_enabled;
 
+  // A bitset indicating which deprecated features to enable in the renderer.

[jamesr, 2014/06/10 17:59:19]

the comment says bitset but the type isn't - it's a vector of bools. a single
bool should be sufficient here - why complicate things? i really hope we don't
use this mechanism more generally

+  // See enum DeprecatedFeature for valid values.
+  std::vector<bool> deprecated_features_to_enable;
+
 #if defined(OS_ANDROID)
   bool text_autosizing_enabled;
   float font_scale_factor;
   float device_scale_adjustment;
   bool force_enable_zoom;
   bool double_tap_to_zoom_enabled;
   bool user_gesture_required_for_media_playback;
   GURL default_video_poster_url;
   bool support_deprecated_target_density_dpi;
   bool use_legacy_background_size_shorthand_behavior;
   bool wide_viewport_quirk;
   bool use_wide_viewport;
   bool viewport_meta_layout_size_quirk;
   bool viewport_meta_merge_content_quirk;
   bool viewport_meta_non_user_scalable_quirk;
   bool viewport_meta_zero_values_quirk;
   bool clobber_user_agent_initial_scale_quirk;
   bool ignore_main_frame_overflow_hidden_quirk;
   bool report_screen_size_in_physical_pixels_quirk;
 #endif
 
   // We try to keep the default values the same as the default values in
   // chrome, except for the cases where it would require lots of extra work for
   // the embedder to use the same default value.
   WebPreferences();
   ~WebPreferences();
 };
 
 #endif  // WEBKIT_COMMON_WEBPREFERENCES_H__