Revert of cc/blimp: Add a LayerTreeHostRemote implementation.

cc/blimp/layer_tree_host_remote.cc

Index: cc/blimp/layer_tree_host_remote.cc
diff --git a/cc/blimp/layer_tree_host_remote.cc b/cc/blimp/layer_tree_host_remote.cc
deleted file mode 100644
index b0158c13682a8e95112f71efb8bf28994eab47e6..0000000000000000000000000000000000000000
--- a/cc/blimp/layer_tree_host_remote.cc
+++ /dev/null
@@ -1,415 +0,0 @@
-// 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/blimp/layer_tree_host_remote.h"
-
-#include "base/atomic_sequence_num.h"
-#include "base/memory/ptr_util.h"
-#include "cc/animation/animation_host.h"
-#include "cc/blimp/compositor_proto_state.h"
-#include "cc/blimp/remote_compositor_bridge.h"
-#include "cc/output/begin_frame_args.h"
-#include "cc/output/compositor_frame_sink.h"
-#include "cc/trees/layer_tree.h"
-#include "cc/trees/layer_tree_host_client.h"
-#include "cc/trees/layer_tree_host_common.h"
-#include "cc/trees/task_runner_provider.h"
-
-namespace cc {
-namespace {
-// We use a 16ms default frame interval because the rate at which the engine
-// produces main frames doesn't matter.
-base::TimeDelta kDefaultFrameInterval = base::TimeDelta::FromMilliseconds(16);
-
-static base::StaticAtomicSequenceNumber s_layer_tree_host_sequence_number;
-}  // namespace
-
-LayerTreeHostRemote::InitParams::InitParams() = default;
-
-LayerTreeHostRemote::InitParams::~InitParams() = default;
-
-LayerTreeHostRemote::LayerTreeHostRemote(InitParams* params)
-    : LayerTreeHostRemote(
-          params,
-          base::MakeUnique<LayerTree>(std::move(params->animation_host),
-                                      this)) {}
-
-LayerTreeHostRemote::LayerTreeHostRemote(InitParams* params,
-                                         std::unique_ptr<LayerTree> layer_tree)
-    : id_(s_layer_tree_host_sequence_number.GetNext() + 1),
-      main_frame_requested_from_bridge_(false),
-      client_(params->client),
-      task_runner_provider_(
-          TaskRunnerProvider::Create(std::move(params->main_task_runner),
-                                     nullptr)),
-      remote_compositor_bridge_(std::move(params->remote_compositor_bridge)),
-      settings_(*params->settings),
-      layer_tree_(std::move(layer_tree)),
-      weak_factory_(this) {
-  DCHECK(task_runner_provider_->IsMainThread());
-  DCHECK(remote_compositor_bridge_);
-  DCHECK(client_);
-  remote_compositor_bridge_->BindToClient(this);
-}
-
-LayerTreeHostRemote::~LayerTreeHostRemote() = default;
-
-int LayerTreeHostRemote::GetId() const {
-  return id_;
-}
-
-int LayerTreeHostRemote::SourceFrameNumber() const {
-  return source_frame_number_;
-}
-
-LayerTree* LayerTreeHostRemote::GetLayerTree() {
-  return layer_tree_.get();
-}
-
-const LayerTree* LayerTreeHostRemote::GetLayerTree() const {
-  return layer_tree_.get();
-}
-
-UIResourceManager* LayerTreeHostRemote::GetUIResourceManager() const {
-  // We shouldn't need a UIResourceManager. The layers which need this
-  // (UIResourceLayers and PaintedScrollbarLayers) are never used by the
-  // renderer compositor in remote mode.
-  NOTREACHED() << "UIResourceManager requested. Unsupported Layer type used";
-  return nullptr;
-}
-
-TaskRunnerProvider* LayerTreeHostRemote::GetTaskRunnerProvider() const {
-  return task_runner_provider_.get();
-}
-
-const LayerTreeSettings& LayerTreeHostRemote::GetSettings() const {
-  return settings_;
-}
-
-void LayerTreeHostRemote::SetFrameSinkId(const FrameSinkId& frame_sink_id) {
-  // We don't need to care about SurfaceLayers. The Surfaces system is
-  // relevant on the client only.
-}
-
-void LayerTreeHostRemote::SetLayerTreeMutator(
-    std::unique_ptr<LayerTreeMutator> mutator) {
-  // TODO(khushalsagar): Compositor-worker not supported. See crbug.com/650876.
-}
-
-void LayerTreeHostRemote::QueueSwapPromise(
-    std::unique_ptr<SwapPromise> swap_promise) {
-  swap_promise_manager_.QueueSwapPromise(std::move(swap_promise));
-}
-
-SwapPromiseManager* LayerTreeHostRemote::GetSwapPromiseManager() {
-  return &swap_promise_manager_;
-}
-
-void LayerTreeHostRemote::SetHasGpuRasterizationTrigger(bool has_trigger) {
-  // TODO(khushalsagar) : Take care of Gpu raster. See crbug.com/650431.
-}
-
-void LayerTreeHostRemote::SetVisible(bool visible) {
-  // The visibility of the compositor is controlled on the client, which is
-  // why this value is not sent there, since the client has the current true
-  // state.
-  visible_ = visible;
-}
-
-bool LayerTreeHostRemote::IsVisible() const {
-  return visible_;
-}
-
-void LayerTreeHostRemote::SetCompositorFrameSink(
-    std::unique_ptr<CompositorFrameSink> compositor_frame_sink) {
-  NOTREACHED()
-      << "The LayerTreeHostClient is never asked for a CompositorFrameSink";
-}
-
-std::unique_ptr<CompositorFrameSink>
-LayerTreeHostRemote::ReleaseCompositorFrameSink() {
-  // Since we never have a CompositorFrameSink, this is always a no-op.
-  return nullptr;
-}
-
-void LayerTreeHostRemote::SetNeedsAnimate() {
-  MainFrameRequested(FramePipelineStage::ANIMATE);
-}
-
-void LayerTreeHostRemote::SetNeedsUpdateLayers() {
-  MainFrameRequested(FramePipelineStage::UPDATE_LAYERS);
-}
-
-void LayerTreeHostRemote::SetNeedsCommit() {
-  MainFrameRequested(FramePipelineStage::COMMIT);
-}
-
-bool LayerTreeHostRemote::BeginMainFrameRequested() const {
-  return requested_pipeline_stage_for_next_frame_ != FramePipelineStage::NONE;
-}
-
-bool LayerTreeHostRemote::CommitRequested() const {
-  return requested_pipeline_stage_for_next_frame_ == FramePipelineStage::COMMIT;
-}
-
-void LayerTreeHostRemote::SetDeferCommits(bool defer_commits) {
-  defer_commits_ = defer_commits;
-  ScheduleMainFrameIfNecessary();
-}
-
-void LayerTreeHostRemote::LayoutAndUpdateLayers() {
-  NOTREACHED() << "Only supported in single-threaded mode and this class"
-               << " does not support single-thread since it is out of process";
-}
-
-void LayerTreeHostRemote::Composite(base::TimeTicks frame_begin_time) {
-  NOTREACHED() << "Only supported in single-threaded mode and this class"
-               << " does not support single-thread since it is out of process";
-}
-
-void LayerTreeHostRemote::SetNeedsRedraw() {
-  // The engine shouldn't need to care about draws. CompositorFrames are never
-  // used here.
-  NOTREACHED();
-}
-
-void LayerTreeHostRemote::SetNeedsRedrawRect(const gfx::Rect& damage_rect) {
-  // The engine shouldn't need to care about draws. CompositorFrames are never
-  // used here.
-  // TODO(khushalsagar): The caller could be waiting for an Ack for this redraw.
-  // We need a better solution for this. See crbug.com/651141.
-  NOTIMPLEMENTED();
-}
-
-void LayerTreeHostRemote::SetNextCommitForcesRedraw() {
-  // Ideally the engine shouldn't need to care about draw requests at all. The
-  // compositor that produces CompositorFrames is on the client and draw
-  // requests should be made directly to it on the client itself.
-  NOTREACHED();
-}
-
-void LayerTreeHostRemote::NotifyInputThrottledUntilCommit() {
-  // This notification is used in the case where the renderer handles an input
-  // event, and needs to send an Ack to the browser when the resulting main
-  // frame is committed. If the compositor is taking too long on the pending
-  // tree, the commit processing will be delayed blocking all input as a result.
-  // So this is used to have the compositor activate the pending tree faster, so
-  // the pending commit can be processed.
-  // In remote mode, we don't send such notifications to the client because the
-  // most likely bottleneck is the transport instead of raster. Also, input is
-  // queued on the client, so if raster does end up being a bottleneck, the
-  // input handling code on the client informs the LayerTreeHostInProcess
-  // directly.
-  NOTIMPLEMENTED();
-}
-
-void LayerTreeHostRemote::UpdateTopControlsState(TopControlsState constraints,
-                                                 TopControlsState current,
-                                                 bool animate) {
-  NOTREACHED() << "Using TopControls animations is not supported";
-}
-
-const base::WeakPtr<InputHandler>& LayerTreeHostRemote::GetInputHandler()
-    const {
-  // Input on the compositor thread is handled on the client, so this is always
-  // null.
-  return input_handler_weak_ptr_;
-}
-
-void LayerTreeHostRemote::DidStopFlinging() {
-  // TODO(khushalsagar): This should not happen. See crbug.com/652000.
-  NOTIMPLEMENTED() << "We shouldn't be sending fling gestures to the engine";
-}
-
-void LayerTreeHostRemote::SetDebugState(
-    const LayerTreeDebugState& debug_state) {
-  // TODO(khushalsagar): Figure out if we need to send these to the client.
-  NOTREACHED();
-}
-
-const LayerTreeDebugState& LayerTreeHostRemote::GetDebugState() const {
-  return debug_state_;
-}
-
-int LayerTreeHostRemote::ScheduleMicroBenchmark(
-    const std::string& benchmark_name,
-    std::unique_ptr<base::Value> value,
-    const MicroBenchmark::DoneCallback& callback) {
-  NOTREACHED();
-  return 0;
-}
-
-bool LayerTreeHostRemote::SendMessageToMicroBenchmark(
-    int id,
-    std::unique_ptr<base::Value> value) {
-  NOTREACHED();
-  return false;
-}
-
-SurfaceSequenceGenerator* LayerTreeHostRemote::GetSurfaceSequenceGenerator() {
-  // TODO(khushalsagar): Eliminate the use of this in blink. See
-  // crbug.com/650876.
-  return &surface_sequence_generator_;
-}
-
-void LayerTreeHostRemote::SetNextCommitWaitsForActivation() {
-  // This is used only by layers that need resource synchronization, i.e.,
-  // texture and surface layers, both of which are not supported.
-  NOTIMPLEMENTED() << "Unsupported Layer type used";
-}
-
-void LayerTreeHostRemote::ResetGpuRasterizationTracking() {
-  // TODO(khushalsagar): Take care of Gpu raster. See crbug.com/650431.
-}
-
-void LayerTreeHostRemote::MainFrameRequested(
-    FramePipelineStage requested_pipeline_stage) {
-  DCHECK_NE(FramePipelineStage::NONE, requested_pipeline_stage);
-
-  swap_promise_manager_.NotifySwapPromiseMonitorsOfSetNeedsCommit();
-
-  // If we are inside a main frame update right now and the requested pipeline
-  // stage is higher than the pipeline stage that we are at, then we'll get to
-  // in this main frame update itself. Update the
-  // |max_pipeline_stage_for_current_frame_| to ensure we go through the
-  // requested pipeline stage.
-  if (current_pipeline_stage_ != FramePipelineStage::NONE &&
-      requested_pipeline_stage > current_pipeline_stage_) {
-    max_pipeline_stage_for_current_frame_ = std::max(
-        max_pipeline_stage_for_current_frame_, requested_pipeline_stage);
-    return;
-  }
-
-  // Update the pipeline stage for the next frame and schedule an update if it
-  // has not been scheduled already.
-  requested_pipeline_stage_for_next_frame_ = std::max(
-      requested_pipeline_stage_for_next_frame_, requested_pipeline_stage);
-
-  ScheduleMainFrameIfNecessary();
-}
-
-void LayerTreeHostRemote::ScheduleMainFrameIfNecessary() {
-  // If the client hasn't asked for a main frame, don't schedule one.
-  if (requested_pipeline_stage_for_next_frame_ == FramePipelineStage::NONE)
-    return;
-
-  // If the client does not want us to run main frame updates right now, don't
-  // schedule one.
-  if (defer_commits_)
-    return;
-
-  // If a main frame request is already pending with the
-  // RemoteCompositorBridge, we don't need to scheduler another one.
-  if (main_frame_requested_from_bridge_)
-    return;
-
-  remote_compositor_bridge_->ScheduleMainFrame();
-  main_frame_requested_from_bridge_ = true;
-}
-
-void LayerTreeHostRemote::BeginMainFrame() {
-  DCHECK(main_frame_requested_from_bridge_);
-  DCHECK(task_runner_provider_->IsMainThread());
-
-  main_frame_requested_from_bridge_ = false;
-
-  // The client might have suspended main frames in the meantime. Early out now,
-  // we'll come back here when they enable main frames again.
-  if (defer_commits_)
-    return;
-
-  DCHECK_EQ(current_pipeline_stage_, FramePipelineStage::NONE);
-  DCHECK_EQ(max_pipeline_stage_for_current_frame_, FramePipelineStage::NONE);
-  DCHECK_NE(requested_pipeline_stage_for_next_frame_, FramePipelineStage::NONE);
-
-  // Start the main frame. It should go till the requested pipeline stage.
-  max_pipeline_stage_for_current_frame_ =
-      requested_pipeline_stage_for_next_frame_;
-  requested_pipeline_stage_for_next_frame_ = FramePipelineStage::NONE;
-
-  client_->WillBeginMainFrame();
-
-  current_pipeline_stage_ = FramePipelineStage::ANIMATE;
-  base::TimeTicks now = base::TimeTicks::Now();
-  client_->BeginMainFrame(BeginFrameArgs::Create(
-      BEGINFRAME_FROM_HERE, now, now + kDefaultFrameInterval,
-      kDefaultFrameInterval, BeginFrameArgs::NORMAL));
-  // We don't run any animations on the layer because threaded animations are
-  // disabled.
-  // TODO(khushalsagar): Revisit this when adding support for animations.
-  DCHECK(!layer_tree_->animation_host()->needs_push_properties());
-  client_->UpdateLayerTreeHost();
-
-  current_pipeline_stage_ = FramePipelineStage::UPDATE_LAYERS;
-  LayerList layer_list;
-  if (max_pipeline_stage_for_current_frame_ >=
-      FramePipelineStage::UPDATE_LAYERS) {
-    // Pull updates for all layers from the client.
-    // TODO(khushalsagar): Investigate the data impact from updating all the
-    // layers. See crbug.com/650885.
-    LayerTreeHostCommon::CallFunctionForEveryLayer(
-        layer_tree_.get(),
-        [&layer_list](Layer* layer) { layer_list.push_back(layer); });
-
-    bool content_is_suitable_for_gpu = false;
-    bool layers_updated =
-        layer_tree_->UpdateLayers(layer_list, &content_is_suitable_for_gpu);
-
-    // If pulling layer updates resulted in any content updates, we need to go
-    // till the commit stage.
-    if (layers_updated)
-      max_pipeline_stage_for_current_frame_ = FramePipelineStage::COMMIT;
-  }
-
-  current_pipeline_stage_ = FramePipelineStage::COMMIT;
-  client_->WillCommit();
-
-  if (max_pipeline_stage_for_current_frame_ < current_pipeline_stage_) {
-    // There is nothing to commit so break the swap promises.
-    swap_promise_manager_.BreakSwapPromises(
-        SwapPromise::DidNotSwapReason::COMMIT_NO_UPDATE);
-
-    // For the client, the commit was successful.
-    MainFrameComplete();
-    return;
-  }
-
-  // TODO(khushalsagar): Serialize current state/reset dirty state tracking and
-  // return the result to the bridge instead.
-  std::unique_ptr<CompositorProtoState> compositor_state =
-      base::MakeUnique<CompositorProtoState>();
-  remote_compositor_bridge_->ProcessCompositorStateUpdate(
-      std::move(compositor_state));
-
-  MainFrameComplete();
-
-  // We can not wait for updates dispatched from the client about the state of
-  // drawing or swaps for frames sent. Since these calls can be used by the
-  // LayerTreeHostClient to throttle further frame updates, so dispatch them
-  // right after the update is processed by the bridge.
-  // TODO(khushalsagar): We can not really know what these callbacks end up
-  // being used for. Consider migrating clients to understand/cope with the fact
-  // that there is no actual compositing happening here.
-  task_runner_provider_->MainThreadTaskRunner()->PostTask(
-      FROM_HERE, base::Bind(&LayerTreeHostRemote::DispatchDrawAndSwapCallbacks,
-                            weak_factory_.GetWeakPtr()));
-}
-
-void LayerTreeHostRemote::MainFrameComplete() {
-  DCHECK_EQ(current_pipeline_stage_, FramePipelineStage::COMMIT);
-
-  current_pipeline_stage_ = FramePipelineStage::NONE;
-  max_pipeline_stage_for_current_frame_ = FramePipelineStage::NONE;
-  source_frame_number_++;
-
-  client_->DidCommit();
-  client_->DidBeginMainFrame();
-}
-
-void LayerTreeHostRemote::DispatchDrawAndSwapCallbacks() {
-  client_->DidCommitAndDrawFrame();
-  client_->DidCompleteSwapBuffers();
-}
-
-}  // namespace cc