compositor-worker: Initialize CW machinery plumbing to compositor and fire CW rAF callbacks.

cc/trees/layer_tree_host_impl.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_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 444 matching lines @@
       input_handler_client_->Animate(monotonic_time);
     }
   }
 
   did_animate |= AnimatePageScale(monotonic_time);
   did_animate |= AnimateLayers(monotonic_time);
   did_animate |= AnimateScrollbars(monotonic_time);
   did_animate |= AnimateTopControls(monotonic_time);
 
   if (active_tree) {
+    did_animate |= Mutate(monotonic_time);
+
     // Animating stuff can change the root scroll offset, so inform the
     // synchronous input handler.
     UpdateRootLayerStateForSynchronousInputHandler();
     if (did_animate) {
       // If the tree changed, then we want to draw at the end of the current
       // frame.
       SetNeedsRedraw();
     }
   }
 }
 
+bool LayerTreeHostImpl::Mutate(base::TimeTicks monotonic_time) {
+  if (!mutator_)
+    return false;
+  TRACE_EVENT0("compositor-worker", "LayerTreeHostImpl::Mutate");
+  if (mutator_->Mutate(monotonic_time))
+    client_->SetNeedsOneBeginImplFrameOnImplThread();
+  return true;
+}
+
+void LayerTreeHostImpl::SetNeedsMutate() {
+  TRACE_EVENT0("compositor-worker", "LayerTreeHostImpl::SetNeedsMutate");
+  client_->SetNeedsOneBeginImplFrameOnImplThread();
+}
+
 bool LayerTreeHostImpl::PrepareTiles() {
   if (!tile_priorities_dirty_)
     return false;
 
   client_->WillPrepareTiles();
   bool did_prepare_tiles = tile_manager_->PrepareTiles(global_tile_state_);
   if (did_prepare_tiles)
     tile_priorities_dirty_ = false;
   client_->DidPrepareTiles();
   return did_prepare_tiles;
@@ skipping 1513 matching lines @@
 
     // Now that we've synced everything from the pending tree to the active
     // tree, rename the pending tree the recycle tree so we can reuse it on the
     // next sync.
     DCHECK(!recycle_tree_);
     pending_tree_.swap(recycle_tree_);
 
     // If we commit to the active tree directly, this is already done during
     // commit.
     ActivateAnimations();
+    Mutate(CurrentBeginFrameArgs().frame_time);
   } else {
     active_tree_->ProcessUIResourceRequestQueue();
   }
 
   // bounds_delta isn't a pushed property, so the newly-pushed property tree
   // won't already account for current bounds_delta values. This needs to
   // happen before calling UpdateViewportContainerSizes().
   active_tree_->UpdatePropertyTreesForBoundsDelta();
   UpdateViewportContainerSizes();
 
@@ skipping 246 matching lines @@
 }
 
 void LayerTreeHostImpl::PostFrameTimingEvents(
     std::unique_ptr<FrameTimingTracker::CompositeTimingSet> composite_events,
     std::unique_ptr<FrameTimingTracker::MainFrameTimingSet> main_frame_events) {
   client_->PostFrameTimingEventsOnImplThread(std::move(composite_events),
                                              std::move(main_frame_events));
 }
 
 void LayerTreeHostImpl::SetLayerTreeMutator(LayerTreeMutator* mutator) {
+  if (mutator == mutator_)
+    return;
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("compositor-worker"),
                "LayerTreeHostImpl::SetLayerTreeMutator");
   mutator_ = mutator;
+  mutator_->SetClient(this);
 }
 
 void LayerTreeHostImpl::CleanUpTileManagerAndUIResources() {
   ClearUIResources();
   tile_manager_->FinishTasksAndCleanUp();
   resource_pool_ = nullptr;
   tile_task_worker_pool_ = nullptr;
   single_thread_synchronous_task_graph_runner_ = nullptr;
   image_decode_controller_ = nullptr;
 }
@@ skipping 835 matching lines @@
   scroll_result.did_overscroll_root = !unused_root_delta.IsZero();
   scroll_result.accumulated_root_overscroll = accumulated_root_overscroll_;
   scroll_result.unused_scroll_delta = unused_root_delta;
 
   if (scroll_result.did_scroll) {
     // Scrolling can change the root scroll offset, so inform the synchronous
     // input handler.
     UpdateRootLayerStateForSynchronousInputHandler();
   }
 
+  // Update compositor worker mutations which may respond to scrolling.
+  Mutate(CurrentBeginFrameArgs().frame_time);
+
   return scroll_result;
 }
 
 // This implements scrolling by page as described here:
 // http://msdn.microsoft.com/en-us/library/windows/desktop/ms645601(v=vs.85).aspx#_win32_The_Mouse_Wheel
 // for events with WHEEL_PAGESCROLL set.
 bool LayerTreeHostImpl::ScrollVerticallyByPage(const gfx::Point& viewport_point,
                                                ScrollDirection direction) {
   DCHECK(wheel_scrolling_);
 
@@ skipping 727 matching lines @@
 }
 
 void LayerTreeHostImpl::SetTreeLayerScrollOffsetMutated(
     int layer_id,
     LayerTreeImpl* tree,
     const gfx::ScrollOffset& scroll_offset) {
   if (!tree)
     return;
 
   LayerImpl* layer = tree->LayerById(layer_id);
-  if (layer)
+  if (layer) {
     layer->OnScrollOffsetAnimated(scroll_offset);
+    // Run mutation callbacks to respond to updated scroll offset.
+    Mutate(CurrentBeginFrameArgs().frame_time);
+  }
 }
 
 void LayerTreeHostImpl::TreeLayerTransformIsPotentiallyAnimatingChanged(
     int layer_id,
     LayerTreeImpl* tree,
     bool is_animating) {
   if (!tree)
     return;
 
   LayerImpl* layer = tree->LayerById(layer_id);
@@ skipping 88 matching lines @@
   return task_runner_provider_->HasImplThread();
 }
 
 bool LayerTreeHostImpl::CommitToActiveTree() const {
   // In single threaded mode we skip the pending tree and commit directly to the
   // active tree.
   return !task_runner_provider_->HasImplThread();
 }
 
 }  // namespace cc