Introduce View::CanProcessEventsWithinSubtree()

ui/views/view.cc

Index: ui/views/view.cc
diff --git a/ui/views/view.cc b/ui/views/view.cc
index 955ad2482d25ba893528f1db1ac3d3bd56e70910..3d902a6487fb939c2f0bd437a5215d4701034f6e 100644
--- a/ui/views/view.cc
+++ b/ui/views/view.cc
@@ -849,6 +849,9 @@ View* View::GetEventHandlerForRect(const gfx::Rect& rect) {
   for (int i = child_count() - 1; i >= 0; --i) {
     View* child = child_at(i);
 
+    if (!child->CanProcessEventsWithinSubtree())
+      continue;
+
     // Ignore any children which are invisible or do not intersect |rect|.
     if (!child->visible())
       continue;
@@ -904,6 +907,10 @@ View* View::GetEventHandlerForRect(const gfx::Rect& rect) {
   return rect_view ? rect_view : point_view;
 }
 
+bool View::CanProcessEventsWithinSubtree() const {
+  return true;
+}
+
 View* View::GetTooltipHandlerForPoint(const gfx::Point& point) {
   if (!HitTestPoint(point))
     return NULL;
@@ -915,6 +922,9 @@ View* View::GetTooltipHandlerForPoint(const gfx::Point& point) {
     if (!child->visible())
       continue;
 
+    if (!child->CanProcessEventsWithinSubtree())
+      continue;
+
     gfx::Point point_in_child_coords(point);
     ConvertPointToTarget(this, child, &point_in_child_coords);
     View* handler = child->GetTooltipHandlerForPoint(point_in_child_coords);