Mus+Ash: propagate Surface ID to parents

services/ui/public/cpp/window.cc

Index: services/ui/public/cpp/window.cc
diff --git a/services/ui/public/cpp/window.cc b/services/ui/public/cpp/window.cc
index 966e51888c18a26e688a91a45c1a44010347b7a9..015852d5156a3174a3ef30da023e2e156b39c79b 100644
--- a/services/ui/public/cpp/window.cc
+++ b/services/ui/public/cpp/window.cc
@@ -12,8 +12,11 @@
 
 #include "base/bind.h"
 #include "base/macros.h"
+#include "cc/surfaces/surface_id.h"
+#include "cc/surfaces/surface_sequence.h"
 #include "services/ui/common/transient_window_utils.h"
 #include "services/ui/public/cpp/property_type_converters.h"
+#include "services/ui/public/cpp/surface_id_handler.h"
 #include "services/ui/public/cpp/window_observer.h"
 #include "services/ui/public/cpp/window_private.h"
 #include "services/ui/public/cpp/window_property.h"
@@ -533,6 +536,11 @@ Window::~Window() {
   if (transient_parent_)
     transient_parent_->LocalRemoveTransientWindow(this);
 
+  // Return the surface reference if there is one.
+  if (!surface_info_.surface_id.is_null())
+    LocalSetSurfaceId(cc::SurfaceId(), cc::SurfaceSequence(), gfx::Size(),
+                      1.0f);
+
   // Remove transient children.
   while (!transient_children_.empty()) {
     Window* transient_child = transient_children_.front();
@@ -582,6 +590,7 @@ Window::Window(WindowTreeClient* client, Id id)
       // Matches aura, see aura::Window for details.
       observers_(base::ObserverList<WindowObserver>::NOTIFY_EXISTING_ONLY),
       input_event_handler_(nullptr),
+      surface_id_handler_(nullptr),
       visible_(false),
       opacity_(1.0f),
       display_id_(display::Display::kInvalidDisplayID),
@@ -790,6 +799,32 @@ void Window::LocalSetSharedProperty(const std::string& name,
       OnWindowSharedPropertyChanged(this, name, old_value_ptr, value));
 }
 
+void Window::LocalSetSurfaceId(const cc::SurfaceId& surface_id,
+                               const cc::SurfaceSequence& surface_sequence,
+                               const gfx::Size& frame_size,
+                               float device_scale_factor) {
+  const cc::SurfaceId& existing_surface_id = surface_info_.surface_id;
+  if (!existing_surface_id.is_null() && existing_surface_id != surface_id) {
+    // Return the existing surface sequence.
+    if (client_) {
+      client_->ReturnSurfaceReference(server_id_,
+                                      surface_info_.surface_sequence);
+    }
+  }
+  if (parent_ && parent_->surface_id_handler_) {
+    if (parent_->surface_id_handler_->OnChildWindowSurfaceCreated(
+            this, surface_id, surface_sequence, frame_size,
+            device_scale_factor)) {
+      // Don't store it on the window if the SurfaceIdHandler has picked it up.
+      surface_info_ = {cc::SurfaceId(), cc::SurfaceSequence(), gfx::Size(),
+                       1.0f};
+      return;
+    }
+  }
+  surface_info_ = {surface_id, surface_sequence, frame_size,
+                   device_scale_factor};
+}
+
 void Window::NotifyWindowStackingChanged() {
   if (stacking_target_) {
     Children::const_iterator window_i = std::find(