Mus+Ash: propagate Surface ID to parents

services/ui/public/cpp/window.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "services/ui/public/cpp/window.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <set>
@@ skipping 515 matching lines @@
     // advances focus. We don't want to randomly pick a Window to get focus, so
     // we update local state only, and wait for the next focus change from the
     // server.
     client_->LocalSetFocus(nullptr);
   }
 
   // Remove from transient parent.
   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();
     LocalRemoveTransientWindow(transient_child);
     transient_child->LocalDestroy();
     DCHECK(transient_children_.empty() ||
            transient_children_.front() != transient_child);
   }
 
   if (parent_)
@@ skipping 237 matching lines @@
     properties_[name] = *value;
   } else if (it != properties_.end()) {
     properties_.erase(it);
   }
 
   FOR_EACH_OBSERVER(
       WindowObserver, observers_,
       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);
+    }
+  }
+  surface_info_ = {surface_id, surface_sequence, frame_size,
+                   device_scale_factor};
+  if (parent_) {
+    // TODO(fsamuel, sadrul): This assumes that observers just observe. If a
+    // ui::Layer is an observer here then it takes ownership of the
+    // SurfaceSequence and returning the refernece.

[sadrul, 2016/10/13 04:26:21]

Each ui::Window could have some explicit SurfaceSequenceHandler that gets
notified here instead (e.g. there's a ui::Window::InputEventHandler for handling
input events).

[Fady Samuel, 2016/10/14 17:42:40]

Done.

+    for (auto& observer : parent_->observers_) {
+      observer.OnChildWindowSurfaceCreated(this, surface_id, surface_sequence,
+                                           frame_size, device_scale_factor);
+    }
+  }
+}
+
 void Window::NotifyWindowStackingChanged() {
   if (stacking_target_) {
     Children::const_iterator window_i = std::find(
         parent()->children().begin(), parent()->children().end(), this);
     DCHECK(window_i != parent()->children().end());
     if (window_i != parent()->children().begin() &&
         (*(window_i - 1) == stacking_target_))
       return;
   }
   RestackTransientDescendants(this, &GetStackingTarget,
@@ skipping 126 matching lines @@
     notifier->NotifyWindowReordered();
 
   return true;
 }
 
 // static
 Window** Window::GetStackingTarget(Window* window) {
   return &window->stacking_target_;
 }
 }  // namespace ui