AXPlatformNodeAuraLinux: add ref_accessible_at_point implementation.

Provide the hit test wrapper for AtkComponent interface, using
an implementation that is compatible with the one in
BrowserAccessibleAuraLinux.

Bug: 784583
Change-Id: Ie1dcae846db9aabf06e636eaf3054c87d2e8bcc9
Reviewed-on: https://chromium-review.googlesource.com/767428
Commit-Queue: José Dapena Paz <jose.dapena@lge.com>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517786}

ui/accessibility/platform/ax_platform_node_auralinux.cc

@@ -271,10 +271,27 @@ static void ax_platform_node_auralinux_get_size(AtkComponent* atk_component,
   obj->GetSize(width, height);
 }
 
+static AtkObject* ax_platform_node_auralinux_ref_accessible_at_point(
+    AtkComponent* atk_component,
+    gint x,
+    gint y,
+    AtkCoordType coord_type) {
+  g_return_val_if_fail(ATK_IS_COMPONENT(atk_component), nullptr);
+  AtkObject* atk_object = ATK_OBJECT(atk_component);
+  ui::AXPlatformNodeAuraLinux* obj =
+      AtkObjectToAXPlatformNodeAuraLinux(atk_object);
+  if (!obj)
+    return nullptr;
+
+  return obj->HitTestSync(x, y, coord_type);
+}
+
 void ax_component_interface_base_init(AtkComponentIface* iface) {
   iface->get_extents = ax_platform_node_auralinux_get_extents;
   iface->get_position = ax_platform_node_auralinux_get_position;
   iface->get_size = ax_platform_node_auralinux_get_size;
+  iface->ref_accessible_at_point =
+      ax_platform_node_auralinux_ref_accessible_at_point;
 }
 
 static const GInterfaceInfo ComponentInfo = {
@@ -747,4 +764,17 @@ void AXPlatformNodeAuraLinux::GetSize(gint* width, gint* height) {
     *height = rect_size.height();
 }
 
+gfx::NativeViewAccessible
+AXPlatformNodeAuraLinux::HitTestSync(gint x, gint y, AtkCoordType coord_type) {
+  if (coord_type == ATK_XY_WINDOW) {
+    if (AtkObject* atk_object = GetParent()) {
+      gfx::Point window_coords = FindAtkObjectParentCoords(atk_object);
+      x += window_coords.x();
+      y += window_coords.y();
+    }
+  }
+
+  return delegate_->HitTestSync(x, y);
+}
+
 }  // namespace ui

ui/accessibility/platform/ax_platform_node_auralinux.h

@@ -33,6 +33,9 @@ class AXPlatformNodeAuraLinux : public AXPlatformNodeBase {
                   AtkCoordType coord_type);
   void GetPosition(gint* x, gint* y, AtkCoordType coord_type);
   void GetSize(gint* width, gint* height);
+  gfx::NativeViewAccessible HitTestSync(gint x,
+                                        gint y,
+                                        AtkCoordType coord_type);
 
   void SetExtentsRelativeToAtkCoordinateType(
       gint* x, gint* y, gint* width, gint* height,