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

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

Index: chrome/browser/chromeos/arc/accessibility/arc_accessibility_helper_bridge.h
diff --git a/chrome/browser/chromeos/arc/accessibility/arc_accessibility_helper_bridge.h b/chrome/browser/chromeos/arc/accessibility/arc_accessibility_helper_bridge.h
index 1cc84f927adfd69f38ac00b08f674971545c3018..345374b456b6ac2c08db984eca23c0cf4ca0f2d1 100644
--- a/chrome/browser/chromeos/arc/accessibility/arc_accessibility_helper_bridge.h
+++ b/chrome/browser/chromeos/arc/accessibility/arc_accessibility_helper_bridge.h
@@ -7,6 +7,8 @@
 
 #include <memory>
 
+#include "chrome/browser/chromeos/arc/accessibility/ax_tree_source_arc.h"
+#include "chrome/browser/ui/app_list/arc/arc_app_list_prefs.h"
 #include "components/arc/arc_service.h"
 #include "components/arc/common/accessibility_helper.mojom.h"
 #include "components/arc/instance_holder.h"
@@ -33,7 +35,8 @@ class ArcAccessibilityHelperBridge
       public mojom::AccessibilityHelperHost,
       public InstanceHolder<mojom::AccessibilityHelperInstance>::Observer,
       public exo::WMHelper::ActivationObserver,
-      public ui::AXHostDelegate {
+      public AXTreeSourceArc::Delegate,
+      public ArcAppListPrefs::Observer {
  public:
   explicit ArcAccessibilityHelperBridge(ArcBridgeService* bridge_service);
   ~ArcAccessibilityHelperBridge() override;
@@ -48,18 +51,27 @@ class ArcAccessibilityHelperBridge
   void OnAccessibilityEvent(
       mojom::AccessibilityEventDataPtr event_data) override;
 
+  // AXTreeSourceArc::Delegate overrides.
+  void OnAction(const ui::AXActionData& data) override;
+
  private:
   // exo::WMHelper::ActivationObserver overrides.
   void OnWindowActivated(aura::Window* gained_active,
                          aura::Window* lost_active) override;
 
-  // AXHostDelegate overrides.
-  void PerformAction(const ui::AXActionData& data) override;
+  // ArcAppListPrefs::Observer overrides.
+  void OnTaskCreated(int task_id,
+                     const std::string& package_name,
+                     const std::string& activity,
+                     const std::string& intent) override;
+  void OnTaskDestroyed(int task_id) override;
+  void OnTaskSetActive(int32_t task_id) override;
 
   mojo::Binding<mojom::AccessibilityHelperHost> binding_;
 
-  std::unique_ptr<AXTreeSourceArc> tree_source_;
-  std::unique_ptr<views::View> focus_stealer_;
+  std::map<int32_t, AXTreeSourceArc*> task_id_to_tree_;

[Luis Héctor Chávez, 2017/04/25 15:27:00]

consider using std::map<int32_t, std::unique_ptr<AXTreeSourceArc>> instead.

[David Tseng, 2017/04/25 22:48:02]

If we trust that ArcAppListPrefs::Observer works as advertised, I think it is
unecessary. Also, I believe the map would still own the tree objects so the
trees would not be deleted until object destruction anyway.

I also added explicit deletion when this object gets destroyed.

[Luis Héctor Chávez, 2017/04/25 23:08:16]

Right, the goal is to remove a bit of such trust and ensure things get destroyed
properly no matter what. The rest of the codebase is slowly moving away from
using raw pointers, so it's better to do so here too.

re: the map owning the tree objects, you can replace any current delete foo;
with a foo.reset(); (or even better, package_name_to_task_id_.erase(id);)

[David Tseng, 2017/04/26 15:29:52]

Ok, if this is the general trend of the codebase, then done.

+  std::map<std::string, int32_t> package_name_to_task_id_;
+  int32_t current_task_id_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcAccessibilityHelperBridge);
 };