Support gcc 10+ toolchains in accessibility headers

flutter/third_party/accessibility/ax/ax_active_popup.h

@@ -5,6 +5,7 @@
 #ifndef UI_ACCESSIBILITY_AX_ACTIVE_POPUP_H_
 #define UI_ACCESSIBILITY_AX_ACTIVE_POPUP_H_
 
+#include <cstdint>
 #include <optional>
 
 #include "ax/ax_export.h"

flutter/third_party/accessibility/ax/ax_event_generator.h

@@ -125,9 +125,13 @@ class AX_EXPORT AXEventGenerator : public AXTreeObserver {
     const EventParams& event_params;
   };
 
-  class AX_EXPORT Iterator
-      : public std::iterator<std::input_iterator_tag, TargetedEvent> {
+  class AX_EXPORT Iterator {
    public:
+    using iterator_category = std::input_iterator_tag;
+    using value_type = TargetedEvent;
+    using difference_type = std::ptrdiff_t;
+    using pointer = TargetedEvent*;
+    using reference = TargetedEvent&;
     Iterator(
         const std::map<AXNode*, std::set<EventParams>>& map,
         const std::map<AXNode*, std::set<EventParams>>::const_iterator& head);

flutter/third_party/accessibility/ax/ax_range.h

@@ -190,8 +190,14 @@ class AXRange {
   //
   // This class allows AXRange to be iterated through all "leaf text ranges"
   // contained between its endpoints, composing the entire range.
-  class Iterator : public std::iterator<std::input_iterator_tag, AXRange> {
+  class Iterator {
    public:
+    using iterator_category = std::input_iterator_tag;
+    using value_type = AXRange;
+    using difference_type = std::ptrdiff_t;
+    using pointer = AXRange*;
+    using reference = AXRange&;
+
     Iterator()
         : current_start_(AXPositionType::CreateNullPosition()),
           iterator_end_(AXPositionType::CreateNullPosition()) {}