MacViews: Implement Full Keyboard Access.

ui/views/view.h

Index: ui/views/view.h
diff --git a/ui/views/view.h b/ui/views/view.h
index 897160ea199e36d922f15edd57ae0e1e646e3653..7376fc81be06419f9a90f8b269f50d1210913952 100644
--- a/ui/views/view.h
+++ b/ui/views/view.h
@@ -115,6 +115,22 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
  public:
   typedef std::vector<View*> Views;
 
+  enum class FocusBehavior {
+    // Use when the view is to be focusable both in default and full keyboard
+    // access mode.
+    ALWAYS,
+
+    // Use when view is never focusable. Default.
+    NEVER,
+
+    // Use when the view is to be made focusable only during full keyboard mode.
+    ACCESSIBLE_ONLY,
+
+    // Use for controls. On Mac, this is the same as ACCESSIBLE_ONLY mode, while
+    // on other platforms it corresponds to ALWAYS.
+    CONTROL,
+  };
+
   struct ViewHierarchyChangedDetails {
     ViewHierarchyChangedDetails()
         : is_add(false),
@@ -768,10 +784,15 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   // IMPORTANT NOTE: loops in the focus hierarchy are not supported.
   void SetNextFocusableView(View* view);
 
+  // Sets |focusable_| and |accessibility_focusable_| corresponding to the given
+  // |focus_behavior|.
+  void SetFocusBehavior(FocusBehavior focus_behavior);
+
   // Sets whether this view is capable of taking focus. It will clear focus if
   // the focused view is set to be non-focusable.
   // Note that this is false by default so that a view used as a container does
   // not get the focus.
+  // TODO(karandeepb): Make private.
   void SetFocusable(bool focusable);
 
   // Returns true if this view is |focusable_|, |enabled_| and drawn.
@@ -785,6 +806,7 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   // full keyboard access, even though it's not normally focusable. It will
   // clear focus if the focused view is set to be non-focusable.
   // Note that this is false by default.
+  // TODO(karandeepb): Make private.
   void SetAccessibilityFocusable(bool accessibility_focusable);
 
   // Convenience method to retrieve the FocusManager associated with the