blimp: Update page load status update indicator to use first paint.

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 <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1444 matching lines @@
   // The LayerTreeHost on the server does not have an impl task runner.
   return compositor_mode_ == CompositorMode::REMOTE &&
          !task_runner_provider_->HasImplThread();
 }
 
 bool LayerTreeHost::IsRemoteClient() const {
   return compositor_mode_ == CompositorMode::REMOTE &&
          task_runner_provider_->HasImplThread();
 }
 
-void LayerTreeHost::ToProtobufForCommit(proto::LayerTreeHost* proto) {
+void LayerTreeHost::ToProtobufForCommit(
+    proto::LayerTreeHost* proto,
+    std::vector<std::unique_ptr<SwapPromise>>* swap_promises) {
   // Not all fields are serialized, as they are either not needed for a commit,
   // or implementation isn't ready yet.
   // Unsupported items:
   // - animations
   // - UI resources
   // - instrumentation of stats
   // - histograms
   // Skipped items:
   // - SwapPromise as they are mostly used for perf measurements.
   // - The bitmap and GPU memory related items.
   // Other notes:
   // - The output surfaces are only valid on the client-side so they are
   //   therefore not serialized.
   // - LayerTreeSettings are needed only during construction of the
   //   LayerTreeHost, so they are serialized outside of the LayerTreeHost
   //   serialization.
   // - The |visible_| flag will be controlled from the client separately and
   //   will need special handling outside of the serialization of the
   //   LayerTreeHost.
   // TODO(nyquist): Figure out how to support animations. See crbug.com/570376.
   TRACE_EVENT0("cc.remote", "LayerTreeHost::ToProtobufForCommit");
+  swap_promises->swap(swap_promise_list_);
+  DCHECK(swap_promise_list_.empty());
+
   proto->set_needs_full_tree_sync(needs_full_tree_sync_);
   proto->set_needs_meta_info_recomputation(needs_meta_info_recomputation_);
   proto->set_source_frame_number(source_frame_number_);
 
   LayerProtoConverter::SerializeLayerHierarchy(root_layer_,
                                                proto->mutable_root_layer());
 
   // layers_that_should_push_properties_ should be serialized before layer
   // properties because it is cleared during the properties serialization.
   for (auto layer : layers_that_should_push_properties_)
@@ skipping 137 matching lines @@
   int seq_num = property_trees_.sequence_number;
   LayerTreeHostCommon::CallFunctionForEveryLayer(this, [seq_num](Layer* layer) {
     layer->set_property_tree_sequence_number(seq_num);
   });
 
   surface_id_namespace_ = proto.surface_id_namespace();
   next_surface_sequence_ = proto.next_surface_sequence();
 }
 
 }  // namespace cc