MacViews: Implement Full Keyboard Access.

ui/views/focus/focus_manager.h

Index: ui/views/focus/focus_manager.h
diff --git a/ui/views/focus/focus_manager.h b/ui/views/focus/focus_manager.h
index debdbe98fff1154e3c3933b9d370ab1dc9462a04..d2595f6b71426f49af4a26a71aa7bb717af36224 100644
--- a/ui/views/focus/focus_manager.h
+++ b/ui/views/focus/focus_manager.h
@@ -201,7 +201,8 @@ class VIEWS_EXPORT FocusManager {
 
   // Restore the view saved with a previous call to StoreFocusedView(). Used
   // when the widget becomes active. Returns true when the previous view was
-  // successfully refocused - otherwise false.
+  // successfully refocused. In case the stored view is no longer focusable,
+  // it advances focus and returns false.
   bool RestoreFocusedView();
 
   // Sets the |view| to be restored when calling RestoreFocusView. This is used
@@ -319,6 +320,12 @@ class VIEWS_EXPORT FocusManager {
                              bool reverse,
                              bool dont_loop);
 
+  bool keyboard_accessible() const { return keyboard_accessible_; }
+
+  // Updates |keyboard_accessible_| to the given value and advances focus if
+  // necessary.
+  void SetKeyboardAccessible(bool keyboard_accessible);
+
  private:
   // Returns the focusable view found in the FocusTraversable specified starting
   // at the specified view. This traverses down along the FocusTraversable
@@ -332,6 +339,10 @@ class VIEWS_EXPORT FocusManager {
   // and should not be processed further.
   bool ProcessArrowKeyTraversal(const ui::KeyEvent& event);
 
+  // Returns true if the |view| is accessibility focusable (checking
+  // IsFocusable() if |keyboard_accessible_| is false on Mac).

[tapted, 2016/05/03 08:08:25]

nit: (this reads a bit funny). Maybe

// Whether |view| is currently focusable per the platform's interpretation of
|keyboard_accesible_|.

[karandeepb, 2016/05/04 01:56:38]

Done.

+  bool IsFocusable(View* view) const;
+
   // Whether arrow key traversal is enabled.
   static bool arrow_key_traversal_enabled_;
 
@@ -364,6 +375,15 @@ class VIEWS_EXPORT FocusManager {
   // See description above getter.
   bool is_changing_focus_;
 
+  // This is true if full keyboard accessibility is needed. This causes
+  // IsAccessibilityFocusable() to be checked rather than IsFocusable(). This
+  // can be set depending on platform constraints. FocusSearch uses this in
+  // addition to its own accessibility mode, which handles accessibility at the
+  // FocusTraversable level. Currently only used on Mac, when Full Keyboard
+  // access is enabled.
+  // Default value is false.
+  bool keyboard_accessible_;
+
   DISALLOW_COPY_AND_ASSIGN(FocusManager);
 };