A11y: Add/refactor methods for manipulating bitfields on AXNodeData.

ui/accessibility/ax_node_data.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.
 
 #ifndef UI_ACCESSIBILITY_AX_NODE_DATA_H_
 #define UI_ACCESSIBILITY_AX_NODE_DATA_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 88 matching lines @@
                            const std::vector<int32_t>& value);
 
   // Convenience functions, mainly for writing unit tests.
   // Equivalent to AddStringAttribute(ATTR_NAME, name).
   void SetName(const std::string& name);
   void SetName(const base::string16& name);
   // Equivalent to AddStringAttribute(ATTR_VALUE, value).
   void SetValue(const std::string& value);
   void SetValue(const base::string16& value);
 
-  // Helper to check whether |state_flag| is set in the given |state|.
-  static bool IsFlagSet(uint32_t state, ui::AXState state_flag);
-
-  // Set or check bits in |state_|.
-  void AddStateFlag(ui::AXState state_flag);
-  bool HasStateFlag(ui::AXState state_flag) const;
+  // Clear all bits in preparation for use of AXNodeData.
+  void ClearBitfields();

[tapted, 2017/05/05 05:53:36]

I feel like this should be called InitState() or PrepareForState() or something
like that. It looks too strange for consumers to set some fields, then call
`ClearBitfields` before setting state-specific stuff -- it's too vague.

Perhaps the constructor should even take an `initial_state` argument (or it
should just set state to 0 and we lose some safety..). That's a decision for the
a11y owners though.

[Patti Lor, 2017/05/08 00:28:08]

Renamed to Init() for now, will link owners this comment.

+  // Set or check bits in |state|.
+  bool HasState(ui::AXState state_flag) const;
+  void AddState(ui::AXState state_flag);
 
   // Return a string representation of this data, for debugging.
   virtual std::string ToString() const;
 
   // As much as possible this should behave as a simple, serializable,
   // copyable struct.
   int32_t id;
   AXRole role;
   uint32_t state;
   std::vector<std::pair<AXStringAttribute, std::string>> string_attributes;
@@ skipping 19 matching lines @@
   // NOTE: this member is a std::unique_ptr because it's rare and gfx::Transform
   // takes up a fair amount of space. The assignment operator and copy
   // constructor both make a duplicate of the owned pointer, so it acts more
   // like a member than a pointer.
   std::unique_ptr<gfx::Transform> transform;
 };
 
 }  // namespace ui
 
 #endif  // UI_ACCESSIBILITY_AX_NODE_DATA_H_