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..ee4ced225e7e908d8ae9bdd4a7e5be6614a8ea36 100644
--- a/ui/views/view.h
+++ b/ui/views/view.h
@@ -751,6 +751,16 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
 
   // Focus ---------------------------------------------------------------------
 
+  enum FocusBehavior {

[tapted, 2016/03/15 05:05:32]

enums are always declared before methods in the class declaration order, so this
should be at the top.

Also I think we should use an `enum class` and refer to these as
FocusBehaviour::ALWAYS  (otherwise we would prefix like FOCUS_ALWAYS, since
ALWAYS/NEVER are a bit too vague to be in the subclass' default namespace)

[karandeepb, 2016/03/17 07:24:47]

Done.

+    ALWAYS,  // Use when the view is to be focusable both in default and full

[tapted, 2016/03/15 05:05:32]

nit: if we can't fit in a line, we usually just comment above and leave a blank
line after the declaration

[karandeepb, 2016/03/17 07:24:47]

Done.

+             // keyboard access mode.
+    NEVER,   // Default.
+    ACCESSIBLE_ONLY,  // Use when the view is to be made focusable only during
+                      // full keyboard mode.
+    CONTROL  // Use for controls. On Mac, this is the same as ACCESSIBLE_ONLY

[tapted, 2016/03/15 05:05:32]

nit: CONTROL,

[karandeepb, 2016/03/17 07:24:47]

Done.

+             // mode, while on other platforms it corresponds to ALWAYS.
+  };
+
   // Returns whether this view currently has the focus.
   virtual bool HasFocus() const;
 
@@ -768,10 +778,15 @@ 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 +800,7 @@ 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