Expand Chrome OS ARC support to create one tree source per package

chrome/browser/chromeos/arc/accessibility/ax_tree_source_arc.h

Index: chrome/browser/chromeos/arc/accessibility/ax_tree_source_arc.h
diff --git a/chrome/browser/chromeos/arc/accessibility/ax_tree_source_arc.h b/chrome/browser/chromeos/arc/accessibility/ax_tree_source_arc.h
index da0ebbc61ef972c0ce24f6ccc046bdb8c0f85e68..08a6018219794d9f56e54220449f594684341cb7 100644
--- a/chrome/browser/chromeos/arc/accessibility/ax_tree_source_arc.h
+++ b/chrome/browser/chromeos/arc/accessibility/ax_tree_source_arc.h
@@ -10,6 +10,7 @@
 #include <vector>
 
 #include "components/arc/common/accessibility_helper.mojom.h"
+#include "ui/accessibility/ax_host_delegate.h"
 #include "ui/accessibility/ax_node.h"
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/accessibility/ax_tree_data.h"
@@ -17,6 +18,14 @@
 #include "ui/accessibility/ax_tree_source.h"
 #include "ui/views/view.h"
 
+namespace aura {
+class Window;
+}
+
+namespace views {
+class View;
+}
+
 namespace arc {
 
 using AXTreeArcSerializer =
@@ -28,17 +37,25 @@ using AXTreeArcSerializer =
 class AXTreeSourceArc
     : public ui::AXTreeSource<mojom::AccessibilityNodeInfoData*,
                               ui::AXNodeData,
-                              ui::AXTreeData> {
+                              ui::AXTreeData>,
+      public ui::AXHostDelegate {
  public:
-  explicit AXTreeSourceArc(int32_t tree_id);
+  class Delegate {
+   public:
+    virtual void OnAction(const ui::AXActionData& data) const = 0;
+  };
+
+  explicit AXTreeSourceArc(Delegate* delegate);
   ~AXTreeSourceArc() override;
 
   // Notify automation of an accessibility event.
   void NotifyAccessibilityEvent(mojom::AccessibilityEventData* event_data);
 
-  int32_t tree_id() const { return tree_id_; }
+  void Focus(aura::Window* window);
 
  private:
+  class FocusStealer;
+
   // AXTreeSource overrides.
   bool GetTreeData(ui::AXTreeData* data) const override;
   mojom::AccessibilityNodeInfoData* GetRoot() const override;
@@ -56,12 +73,12 @@ class AXTreeSourceArc
   void SerializeNode(mojom::AccessibilityNodeInfoData* node,
                      ui::AXNodeData* out_data) const override;
 
+  // AXHostDelegate overrides.
+  void PerformAction(const ui::AXActionData& data) override;
+
   // Resets tree state.
   void Reset();
 
-  // The id of this tree.
-  int32_t tree_id_;
-
   // Maps an AccessibilityNodeInfo to its tree data.
   std::map<int32_t, mojom::AccessibilityNodeInfoData*> tree_map_;
   std::map<int32_t, int32_t> parent_map_;
@@ -69,6 +86,11 @@ class AXTreeSourceArc
   int32_t root_id_;
   int32_t focused_node_id_;
 
+  // A delegate that handles accessibility actions on behalf of this tree. The
+  // delegate is valid during the lifetime of this tree.
+  const Delegate* delegate_;

[Luis Héctor Chávez, 2017/04/26 15:34:59]

nit: const Delegate* const delegate_; (or Delegate* const delegate_)

the const after the pointer means that you won't change the address of the
pointer. You're only setting |delegate_| on the ctor.

If you use the second variant, you don't need to make Delegate::OnAction const
(none of the other Delegates I've seen have const methods, so that would make it
more consistent with the rest of the codebase).

[David Tseng, 2017/04/28 00:27:44]

Yup; I know what void* const means :).

If we're strict here, then I guess both const specifiers apply since the
delegate should never be modifying its own state (if one were to extend the
methods it has), and I never actually reassign the pointer itself.

+  std::unique_ptr<FocusStealer> focus_stealer_;
+
   DISALLOW_COPY_AND_ASSIGN(AXTreeSourceArc);
 };