Avoid destroying surface before the parent surface stops referencing it.

cc/surfaces/surface_manager.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_manager.h"
 
 #include "base/logging.h"
 #include "cc/surfaces/surface.h"
+#include "cc/surfaces/surface_id_allocator.h"
 
 namespace cc {
 
 SurfaceManager::SurfaceManager() {
   thread_checker_.DetachFromThread();
 }
 
 SurfaceManager::~SurfaceManager() {
   DCHECK(thread_checker_.CalledOnValidThread());
+  for (SurfaceDestroyList::iterator it = surfaces_to_destroy_.begin();
+       it != surfaces_to_destroy_.end();
+       ++it) {
+    DeregisterSurface(it->first->surface_id());
+    delete it->first;
+  }
 }
 
 void SurfaceManager::RegisterSurface(Surface* surface) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(surface);
   DCHECK(!surface_map_.count(surface->surface_id()));
   surface_map_[surface->surface_id()] = surface;
 }
 
 void SurfaceManager::DeregisterSurface(SurfaceId surface_id) {
   DCHECK(thread_checker_.CalledOnValidThread());
   SurfaceMap::iterator it = surface_map_.find(surface_id);
   DCHECK(it != surface_map_.end());
   surface_map_.erase(it);
 }
 
+void SurfaceManager::DestroyOnSequence(
+    scoped_ptr<Surface> surface,
+    const std::set<SurfaceSequence>& dependency_set) {
+  surfaces_to_destroy_.push_back(make_pair(surface.release(), dependency_set));
+  SearchForSatisfaction();
+}
+
+void SurfaceManager::DidSatisfySequences(SurfaceId id,
+                                         std::vector<uint32_t>* sequence) {
+  for (std::vector<uint32_t>::iterator it = sequence->begin();
+       it != sequence->end();
+       ++it) {
+    satisfied_sequences_.insert(
+        SurfaceSequence(SurfaceIdAllocator::NamespaceForId(id), *it));
+  }
+  sequence->clear();
+  SearchForSatisfaction();
+}
+
+void SurfaceManager::SearchForSatisfaction() {
+  for (SurfaceDestroyList::iterator dest_it = surfaces_to_destroy_.begin();
+       dest_it != surfaces_to_destroy_.end();) {
+    std::set<SurfaceSequence>& dependency_set = dest_it->second;
+
+    for (std::set<SurfaceSequence>::iterator it = dependency_set.begin();
+         it != dependency_set.end();) {
+      if (satisfied_sequences_.count(*it) > 0) {
+        satisfied_sequences_.erase(*it);
+        std::set<SurfaceSequence>::iterator old_it = it;
+        ++it;
+        dependency_set.erase(old_it);
+      } else {
+        ++it;
+      }
+    }
+    if (dependency_set.empty()) {
+      scoped_ptr<Surface> surf(dest_it->first);
+      DeregisterSurface(surf->surface_id());
+      dest_it = surfaces_to_destroy_.erase(dest_it);
+    } else {
+      ++dest_it;
+    }
+  }
+}
+
 Surface* SurfaceManager::GetSurfaceForId(SurfaceId surface_id) {
   DCHECK(thread_checker_.CalledOnValidThread());
   SurfaceMap::iterator it = surface_map_.find(surface_id);
   if (it == surface_map_.end())
     return NULL;
   return it->second;
 }
 
 void SurfaceManager::SurfaceModified(SurfaceId surface_id) {
   DCHECK(thread_checker_.CalledOnValidThread());
   FOR_EACH_OBSERVER(
       SurfaceDamageObserver, observer_list_, OnSurfaceDamaged(surface_id));
 }
 
 }  // namespace cc