Views a11y: Add comment to explain usage of AXNodeData's |state| member.

ui/accessibility/ax_node_data.cc

 // 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.
 
 #include "ui/accessibility/ax_node_data.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <set>
@@ skipping 42 matching lines @@
   return std::find_if(vector.begin(),
                       vector.end(),
                       FirstIs<FirstType, SecondType>(first));
 }
 
 }  // namespace
 
 AXNodeData::AXNodeData()
     : id(-1),
       role(AX_ROLE_UNKNOWN),
+      // Turn on all flags to more easily catch bugs where no flags are set.
+      // This will be cleared back to a 0-state before use.
       state(0xFFFFFFFF),
       offset_container_id(-1) {
 }
 
 AXNodeData::~AXNodeData() {
 }
 
 AXNodeData::AXNodeData(const AXNodeData& other) {
   id = other.id;
   role = other.role;
@@ skipping 708 matching lines @@
     }
   }
 
   if (!child_ids.empty())
     result += " child_ids=" + IntVectorToString(child_ids);
 
   return result;
 }
 
 }  // namespace ui