Surface Synchronization: Distinguish between dependencies and references

cc/surfaces/surface_factory.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 "cc/surfaces/surface_factory.h"
 
 #include <utility>
 
 #include "base/memory/ptr_util.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 87 matching lines @@
 }
 
 void SurfaceFactory::RefResources(const TransferableResourceArray& resources) {
   holder_.RefResources(resources);
 }
 
 void SurfaceFactory::UnrefResources(const ReturnedResourceArray& resources) {
   holder_.UnrefResources(resources);
 }
 
-void SurfaceFactory::OnReferencedSurfacesChanged(
-    Surface* surface,
-    const std::vector<SurfaceId>* active_referenced_surfaces,
-    const std::vector<SurfaceId>* pending_referenced_surfaces) {
-  client_->ReferencedSurfacesChanged(surface->surface_id().local_surface_id(),
-                                     active_referenced_surfaces,
-                                     pending_referenced_surfaces);
-}
-
 void SurfaceFactory::OnSurfaceActivated(Surface* surface) {
   DCHECK(surface->HasActiveFrame());
-  if (seen_first_frame_activation_)
-    return;
+  if (!seen_first_frame_activation_) {
+    seen_first_frame_activation_ = true;
 
-  seen_first_frame_activation_ = true;
+    const CompositorFrame& frame = surface->GetActiveFrame();
+    // CompositorFrames might not be populated with a RenderPass in unit tests.
+    gfx::Size frame_size;
+    if (!frame.render_pass_list.empty())
+      frame_size = frame.render_pass_list.back()->output_rect.size();
 
-  const CompositorFrame& frame = surface->GetActiveFrame();
-  // CompositorFrames might not be populated with a RenderPass in unit tests.
-  gfx::Size frame_size;
-  if (!frame.render_pass_list.empty())
-    frame_size = frame.render_pass_list.back()->output_rect.size();
-
-  // SurfaceCreated only applies for the first Surface activation. Thus,
-  // SurfaceFactory stops observing new activations after the first one.
-  manager_->SurfaceCreated(SurfaceInfo(
-      surface->surface_id(), frame.metadata.device_scale_factor, frame_size));
+    // SurfaceCreated only applies for the first Surface activation. Thus,
+    // SurfaceFactory stops observing new activations after the first one.
+    manager_->SurfaceCreated(SurfaceInfo(
+        surface->surface_id(), frame.metadata.device_scale_factor, frame_size));
+  }
+  // Fire SurfaceCreated first so that a temporary reference is added before it
+  // is potentially transformed into a real reference by the client.
+  client_->ReferencedSurfacesChanged(surface->surface_id().local_surface_id(),
+                                     surface->active_referenced_surfaces());
 }
 
 void SurfaceFactory::OnSurfaceDependenciesChanged(
     Surface* surface,
     const SurfaceDependencies& added_dependencies,
     const SurfaceDependencies& removed_dependencies) {}
 
 void SurfaceFactory::OnSurfaceDiscarded(Surface* surface) {}
 
 std::unique_ptr<Surface> SurfaceFactory::Create(
     const LocalSurfaceId& local_surface_id) {
   seen_first_frame_activation_ = false;
   std::unique_ptr<Surface> surface =
       manager_->CreateSurface(weak_factory_.GetWeakPtr(), local_surface_id);
   surface->AddObserver(this);
   return surface;
 }
 
 void SurfaceFactory::Destroy(std::unique_ptr<Surface> surface) {
   surface->RemoveObserver(this);
   manager_->DestroySurface(std::move(surface));
 }
 
 }  // namespace cc