cc/blimp: Add synchronization for scroll/scale state.

cc/test/layer_tree_host_remote_for_testing.cc

 // Copyright 2016 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/test/layer_tree_host_remote_for_testing.h"
 
 #include "base/memory/ptr_util.h"
 #include "cc/animation/animation_host.h"
 #include "cc/blimp/compositor_proto_state.h"
 #include "cc/blimp/compositor_state_deserializer.h"
@@ skipping 44 matching lines @@
     : public LayerTreeHostClient {
  public:
   LayerTreeHostInProcessClient(
       LayerTreeHostRemoteForTesting* layer_tree_host_remote)
       : layer_tree_host_remote_(layer_tree_host_remote) {}
 
   ~LayerTreeHostInProcessClient() override = default;
 
   void WillBeginMainFrame() override {}
   void BeginMainFrame(const BeginFrameArgs& args) override {
-    // Send any scroll/scale updates first.
-    layer_tree_host_remote_->ApplyUpdatesFromInProcessHost();
-    layer_tree_host_remote_->BeginMainFrame();
+    layer_tree_host_remote_->BeginRemoteMainFrame();
   }
   void BeginMainFrameNotExpectedSoon() override {}
   void DidBeginMainFrame() override {}
   void UpdateLayerTreeHost() override {}
   void ApplyViewportDeltas(const gfx::Vector2dF& inner_delta,
                            const gfx::Vector2dF& outer_delta,
                            const gfx::Vector2dF& elastic_overscroll_delta,
                            float page_scale,
                            float top_controls_delta) override {}
   void RequestNewCompositorFrameSink() override {
@@ skipping 123 matching lines @@
       static_cast<RemoteCompositorBridgeImpl*>(remote_compositor_bridge());
   remote_compositor_bridge_impl->SetRemoteHost(this);
 
   layer_tree_host_in_process_ = CreateLayerTreeHostInProcess(
       layer_tree_host_in_process_client_.get(), task_graph_runner,
       GetSettings(), main_task_runner, impl_task_runner);
 
   compositor_state_deserializer_ =
       base::MakeUnique<CompositorStateDeserializer>(
           layer_tree_host_in_process_.get(),
-          image_serialization_processor_->CreateClientPictureCache(),
-          base::Bind(&LayerTreeHostRemoteForTesting::LayerDidScroll,
-                     base::Unretained(this)),
-          this);
+          image_serialization_processor_->CreateClientPictureCache(), this);
 
   // Override the LayerFactory since a lot of tests rely on the fact that Layers
   // and LayerImpls have matching ids.
   compositor_state_deserializer_->SetLayerFactoryForTesting(
       base::MakeUnique<RemoteClientLayerFactory>());
 
   // Override the TaskRunnerProvider since tests may rely on accessing the impl
   // task runner using it.
   SetTaskRunnerProviderForTesting(
       TaskRunnerProvider::Create(main_task_runner, impl_task_runner));
@@ skipping 10 matching lines @@
 
   params.client = client;
   params.task_graph_runner = task_graph_runner;
   params.settings = &settings;
   params.main_task_runner = main_task_runner;
   params.animation_host = AnimationHost::CreateMainInstance();
 
   return LayerTreeHostInProcess::CreateThreaded(impl_task_runner, &params);
 }
 
+void LayerTreeHostRemoteForTesting::DidUpdateLocalState() {
+  client_state_dirty_ = true;
+}
+
 void LayerTreeHostRemoteForTesting::DispatchDrawAndSubmitCallbacks() {
   // Don't dispatch callbacks right after the commit on the remote host. Since
   // tests rely on CompositorFrames being swapped on the CompositorFrameSink,
   // we wait for these callbacks from the LayerTreeHostInProcess.
 }
 
-bool LayerTreeHostRemoteForTesting::ShouldRetainClientScroll(
-    int engine_layer_id,
-    const gfx::ScrollOffset& new_offset) {
-  return false;
+void LayerTreeHostRemoteForTesting::RemoteHostNeedsMainFrame() {
+  layer_tree_host_in_process_->SetNeedsAnimate();
 }
 
-bool LayerTreeHostRemoteForTesting::ShouldRetainClientPageScale(
-    float new_page_scale) {
-  return false;
-}
+void LayerTreeHostRemoteForTesting::BeginRemoteMainFrame() {
+  // Send scroll/scale updates first if modified on the impl thread.
+  if (client_state_dirty_) {
+    client_state_dirty_ = false;
+    proto::ClientStateUpdate client_state_update;
+    compositor_state_deserializer_->PullClientStateUpdate(&client_state_update);
+    ApplyStateUpdateFromClient(client_state_update);
 
-void LayerTreeHostRemoteForTesting::LayerDidScroll(int engine_layer_id) {
-  layers_scrolled_[engine_layer_id] =
-      compositor_state_deserializer_->GetLayerForEngineId(engine_layer_id)
-          ->scroll_offset();
-}
+    // Tell the host on the client that the updates were applied to the state
+    // on the remote host, in case the main frame on the remote host is aborted.
+    compositor_state_deserializer_->DidApplyStateUpdatesOnEngine();
+  }
 
-void LayerTreeHostRemoteForTesting::ApplyUpdatesFromInProcessHost() {
-  ApplyScrollAndScaleUpdateFromClient(
-      layers_scrolled_,
-      layer_tree_host_in_process_->GetLayerTree()->page_scale_factor());
-  layers_scrolled_.clear();
-}
-
-void LayerTreeHostRemoteForTesting::RemoteHostNeedsMainFrame() {
-  layer_tree_host_in_process_->SetNeedsAnimate();
+  BeginMainFrame();
 }
 
 void LayerTreeHostRemoteForTesting::ProcessRemoteCompositorUpdate(
     std::unique_ptr<CompositorProtoState> compositor_proto_state) {
   DCHECK(layer_tree_host_in_process_->CommitRequested());
+
   // Deserialize the update from the remote host into client side LTH in
   // process. This bypasses the network layer.
   const proto::LayerTreeHost& layer_tree_host_proto =
       compositor_proto_state->compositor_message->layer_tree_host();
   compositor_state_deserializer_->DeserializeCompositorUpdate(
       layer_tree_host_proto);
 
   const proto::LayerUpdate& layer_updates =
       compositor_proto_state->compositor_message->layer_tree_host()
           .layer_updates();
@@ skipping 11 matching lines @@
   }
 
   // The only case where the remote host would give a compositor update is if
   // they wanted the main frame to go till the commit pipeline stage. So
   // request one to make sure that the in process main frame also goes till
   // the commit step.
   layer_tree_host_in_process_->SetNeedsCommit();
 }
 
 }  // namespace cc