Add 4 ARIA 1.1 attributes using new sparse attribute interface.

content/renderer/accessibility/blink_ax_tree_source.cc

Index: content/renderer/accessibility/blink_ax_tree_source.cc
diff --git a/content/renderer/accessibility/blink_ax_tree_source.cc b/content/renderer/accessibility/blink_ax_tree_source.cc
index e6c45067b5254fef2441ef94681aa4fa88e99227..f1537b903873ffb440efc3c3835b38e9b2e685aa 100644
--- a/content/renderer/accessibility/blink_ax_tree_source.cc
+++ b/content/renderer/accessibility/blink_ax_tree_source.cc
@@ -78,12 +78,25 @@ class AXContentNodeDataSparseAttributeAdapter
 
   void addBoolAttribute(blink::WebAXBoolAttribute attribute,
                         bool value) override {
-    NOTREACHED();
+    switch (attribute) {
+      default:
+        NOTREACHED();
+    }
   }
 
   void addStringAttribute(blink::WebAXStringAttribute attribute,
                           const blink::WebString& value) override {
-    NOTREACHED();
+    switch (attribute) {
+      case blink::WebAXStringAttribute::AriaKeyShortcuts:
+        // TODO(dmazzoni): implement aria-keyshortcuts. http://crbug.com/644766
+        break;
+      case blink::WebAXStringAttribute::AriaRoleDescription:
+        // TODO(dmazzoni): implement aria-roledescription.
+        // http://crbug.com/644766
+        break;
+      default:
+        NOTREACHED();
+    }
   }
 
   void addObjectAttribute(blink::WebAXObjectAttribute attribute,
@@ -92,6 +105,9 @@ class AXContentNodeDataSparseAttributeAdapter
       case blink::WebAXObjectAttribute::AriaActiveDescendant:
         dst_->AddIntAttribute(ui::AX_ATTR_ACTIVEDESCENDANT_ID, value.axID());
         break;
+      case blink::WebAXObjectAttribute::AriaErrorMessage:
+        // TODO

[aboxhall, 2017/01/27 01:41:21]

TODO needs completing (still TODO?)

[dmazzoni, 2017/01/31 00:31:54]

Coming in the immediately-following change:

https://codereview.chromium.org/2587343004/

+        break;
       default:
         NOTREACHED();
     }
@@ -105,6 +121,9 @@ class AXContentNodeDataSparseAttributeAdapter
         AddIntListAttributeFromWebObjects(ui::AX_ATTR_CONTROLS_IDS, value,
                                           dst_);
         break;
+      case blink::WebAXObjectVectorAttribute::AriaDetails:
+        // TODO
+        break;
       case blink::WebAXObjectVectorAttribute::AriaFlowTo:
         AddIntListAttributeFromWebObjects(ui::AX_ATTR_FLOWTO_IDS, value, dst_);
         break;