Add a window property to associate RWHVA with its child AX tree ID

content/browser/renderer_host/render_widget_host_view_base.h

Index: content/browser/renderer_host/render_widget_host_view_base.h
diff --git a/content/browser/renderer_host/render_widget_host_view_base.h b/content/browser/renderer_host/render_widget_host_view_base.h
index 657ad2027f14a0c5c9deec9f61056a39592cddd5..37bba67bf4cba068d54a0f56008079153abf0bae 100644
--- a/content/browser/renderer_host/render_widget_host_view_base.h
+++ b/content/browser/renderer_host/render_widget_host_view_base.h
@@ -31,6 +31,7 @@
 #include "third_party/WebKit/public/web/WebPopupType.h"
 #include "third_party/WebKit/public/web/WebTextDirection.h"
 #include "third_party/skia/include/core/SkImageInfo.h"
+#include "ui/accessibility/ax_tree_id_registry.h"
 #include "ui/base/ime/text_input_mode.h"
 #include "ui/base/ime/text_input_type.h"
 #include "ui/display/display.h"
@@ -210,7 +211,7 @@ class CONTENT_EXPORT RenderWidgetHostViewBase : public RenderWidgetHostView,
   virtual gfx::Point AccessibilityOriginInScreen(const gfx::Rect& bounds);
   virtual gfx::AcceleratedWidget AccessibilityGetAcceleratedWidget();
   virtual gfx::NativeViewAccessible AccessibilityGetNativeViewAccessible();
-
+  virtual void UpdateAXTreeID(ui::AXTreeIDRegistry::AXTreeID id) {}

[sky, 2017/03/08 23:51:12]

SetMainFrameAXTreeID ?

[dmazzoni, 2017/03/09 00:18:19]

Sure, done

   // Informs that the focused DOM node has changed.
   virtual void FocusedNodeChanged(bool is_editable_node,
                                   const gfx::Rect& node_bounds_in_screen) {}