Allow layers to signal that additional sequences are needed before surface destruction

cc/trees/layer_tree_host.cc

Index: cc/trees/layer_tree_host.cc
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index 4808117756acd65a3d578450b7f1cbb4f91f3a98..c7b90856f854b8417589ebed661f9e58915b2a65 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -127,7 +127,9 @@ LayerTreeHost::LayerTreeHost(LayerTreeHostClient* client,
       id_(s_layer_tree_host_sequence_number.GetNext() + 1),
       next_commit_forces_redraw_(false),
       shared_bitmap_manager_(shared_bitmap_manager),
-      gpu_memory_buffer_manager_(gpu_memory_buffer_manager) {
+      gpu_memory_buffer_manager_(gpu_memory_buffer_manager),
+      surface_id_namespace_(0),
+      next_surface_sequence_(1) {

[jamesr, 2014/10/29 00:51:10]

these two are uints, so 0u / 1u

   if (settings_.accelerated_animation_enabled)
     animation_registrar_ = AnimationRegistrar::Create();
   rendering_stats_instrumentation_->set_record_rendering_stats(
@@ -166,15 +168,15 @@ void LayerTreeHost::InitializeProxy(scoped_ptr<Proxy> proxy) {
 LayerTreeHost::~LayerTreeHost() {
   TRACE_EVENT0("cc", "LayerTreeHost::~LayerTreeHost");
 
-  DCHECK(swap_promise_monitor_.empty());
-
-  BreakSwapPromises(SwapPromise::COMMIT_FAILS);
-
   overhang_ui_resource_ = nullptr;
 
   if (root_layer_.get())
     root_layer_->SetLayerTreeHost(NULL);
 
+  DCHECK(swap_promise_monitor_.empty());
+
+  BreakSwapPromises(SwapPromise::COMMIT_FAILS);
+
   if (proxy_) {
     DCHECK(proxy_->IsMainThread());
     proxy_->Stop();
@@ -1338,4 +1340,12 @@ void LayerTreeHost::BreakSwapPromises(SwapPromise::DidNotSwapReason reason) {
   swap_promise_list_.clear();
 }
 
+void LayerTreeHost::set_surface_id_namespace(uint32_t id_namespace) {
+  surface_id_namespace_ = id_namespace;
+}
+
+SurfaceSequence LayerTreeHost::CreateSurfaceSequence() {
+  return SurfaceSequence(surface_id_namespace_, ++next_surface_sequence_);
+}
+
 }  // namespace cc