Implement accessible states and notifications for the tab strip.

ui/accessibility/ax_enums.idl

Index: ui/accessibility/ax_enums.idl
diff --git a/ui/accessibility/ax_enums.idl b/ui/accessibility/ax_enums.idl
index adab1aa1f2789fadcbf2e489f148d044ec791113..2605c6afec31049da5f761ece1c478f902d1964a 100644
--- a/ui/accessibility/ax_enums.idl
+++ b/ui/accessibility/ax_enums.idl
@@ -7,42 +7,55 @@
 [camel_case_enum_to_string=true] namespace ui {
 
   // For new entries to the following three enums, also add to
-  // chrome/common/extensions/apis/automation.idl.
+  // chrome/common/extensions/api/automation.idl.
+  //
+  // Explanation of the comments next to these events:
+  //
+  // Web: this event is only used in web content. Unless a specific platform
+  //      is specified, it fires a native event on multiple platforms.
+  //
+  // Native: this event is only used in native UI.
+  //
+  // Implicit: it would be cleaner if we just updated the AX node
+  //     and each platform fired the appropriate events to indicate which
+  //     platform-specific attributes changed.
+  //
+  // If unspecified, the event is used across web and native on multiple
+  // platforms.
   enum AXEvent {
-    activedescendantchanged,
+    activedescendantchanged,   // Web
     alert,
-    aria_attribute_changed,
-    autocorrection_occured,
-    blur,
-    checked_state_changed,
+    aria_attribute_changed,    // Implicit
+    autocorrection_occured,    // Unknown: http://crbug.com/392498
+    blur,                      // Remove: http://crbug.com/392502
+    checked_state_changed,     // Implicit
     children_changed,
-    destroyed,
     focus,
-    hide,
+    hide,                      // Remove: http://crbug.com/392502
     hover,
-    invalid_status_changed,
-    layout_complete,
-    live_region_changed,
-    load_complete,
-    location_changed,
-    menu_end,
-    menu_list_item_selected,
-    menu_list_value_changed,
-    menu_popup_end,
-    menu_popup_start,
-    menu_start,
-    row_collapsed,
-    row_count_changed,
-    row_expanded,
-    scroll_position_changed,
-    scrolled_to_anchor,
-    selected_children_changed,
-    selected_text_changed,
-    selection_changed,
-    show,
+    invalid_status_changed,    // Implicit
+    layout_complete,           // Web
+    live_region_changed,       // Web
+    load_complete,             // Web
+    location_changed,          // Web
+    menu_end,                  // Native / Win
+    menu_list_item_selected,   // Web
+    menu_list_value_changed,   // Web
+    menu_popup_end,            // Native / Win
+    menu_popup_start,          // Native / Win
+    menu_start,                // Native / Win
+    row_collapsed,             // Web / Mac
+    row_count_changed,         // Web / Mac
+    row_expanded,              // Web / Mac
+    scroll_position_changed,   // Web
+    scrolled_to_anchor,        // Web
+    selected_children_changed, // Web
+    selection,                 // Native
+    selection_add,             // Native
+    selection_remove,          // Native
+    show,                      // Remove: http://crbug.com/392502
     text_changed,
-    text_inserted,
-    text_removed,
+    text_selection_changed,
     value_changed
   };