Update from https://crrev.com/303153

cc/trees/layer_tree_host.cc

 // Copyright 2011 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/trees/layer_tree_host.h"
 
 #include <algorithm>
 #include <stack>
 #include <string>
 
@@ skipping 110 matching lines @@
       content_is_suitable_for_gpu_rasterization_(true),
       gpu_rasterization_histogram_recorded_(false),
       background_color_(SK_ColorWHITE),
       has_transparent_background_(false),
       partial_texture_update_requests_(0),
       in_paint_layer_contents_(false),
       total_frames_used_for_lcd_text_metrics_(0),
       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_(0u),
+      next_surface_sequence_(1u) {
   if (settings_.accelerated_animation_enabled)
     animation_registrar_ = AnimationRegistrar::Create();
   rendering_stats_instrumentation_->set_record_rendering_stats(
       debug_state_.RecordRenderingStats());
 }
 
 void LayerTreeHost::InitializeThreaded(
     scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner) {
   InitializeProxy(
@@ skipping 18 matching lines @@
   proxy_->Start();
   if (settings_.accelerated_animation_enabled) {
     animation_registrar_->set_supports_scroll_animations(
         proxy_->SupportsImplScrolling());
   }
 }
 
 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();
   }
 
   // We must clear any pointers into the layer tree prior to destroying it.
   RegisterViewportLayers(NULL, NULL, NULL);
 
   if (root_layer_.get()) {
     // The layer tree must be destroyed before the layer tree host. We've
@@ skipping 1140 matching lines @@
   DCHECK(swap_promise);
   swap_promise_list_.push_back(swap_promise.Pass());
 }
 
 void LayerTreeHost::BreakSwapPromises(SwapPromise::DidNotSwapReason reason) {
   for (size_t i = 0; i < swap_promise_list_.size(); i++)
     swap_promise_list_[i]->DidNotSwap(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