cc: Split animating and drawing into separate actions

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 <algorithm>
 #include <limits>
 
 #include "base/basictypes.h"
@@ skipping 452 matching lines @@
     page_scale_animation_->ZoomWithAnchor(anchor,
                                           page_scale,
                                           duration.InSecondsF());
   } else {
     gfx::Vector2dF scaled_target_offset = target_offset;
     page_scale_animation_->ZoomTo(scaled_target_offset,
                                   page_scale,
                                   duration.InSecondsF());
   }
 
-  SetNeedsRedraw();
+  SetNeedsAnimate();
   client_->SetNeedsCommitOnImplThread();
   client_->RenewTreePriority();
 }
 
-void LayerTreeHostImpl::ScheduleAnimation() {
-  SetNeedsRedraw();
-}
-
 bool LayerTreeHostImpl::HaveTouchEventHandlersAt(
     const gfx::Point& viewport_point) {
   if (!settings_.touch_hit_testing)
     return true;
   if (!EnsureRenderSurfaceLayerList())
     return false;
 
   gfx::PointF device_viewport_point =
       gfx::ScalePoint(viewport_point, device_scale_factor_);
 
@@ skipping 1219 matching lines @@
   // draw or timer tick.
   if (!visible_)
     ManageTiles();
 
   if (!renderer_)
     return;
 
   renderer_->SetVisible(visible);
 }
 
+void LayerTreeHostImpl::SetNeedsAnimate() {
+  NotifySwapPromiseMonitorsOfSetNeedsRedraw();
+  client_->SetNeedsAnimateOnImplThread();
+}
+
 void LayerTreeHostImpl::SetNeedsRedraw() {
   NotifySwapPromiseMonitorsOfSetNeedsRedraw();
   client_->SetNeedsRedrawOnImplThread();
 }
 
 ManagedMemoryPolicy LayerTreeHostImpl::ActualManagedMemoryPolicy() const {
   ManagedMemoryPolicy actual = cached_managed_memory_policy_;
   // TODO(ernstm): The second condition disables pre-painting for all layers
   // when GPU rasterization is enabled. Once we selectively enable GPU
   // rasterization per layer, we also need to disable pre-painting selectively:
@@ skipping 975 matching lines @@
       monotonic_time_for_cc_animations);
 
   ScrollViewportBy(next_scroll - scroll_total);
   SetNeedsRedraw();
 
   if (page_scale_animation_->IsAnimationCompleteAtTime(
           monotonic_time_for_cc_animations)) {
     page_scale_animation_.reset();
     client_->SetNeedsCommitOnImplThread();
     client_->RenewTreePriority();
+  } else {
+    SetNeedsAnimate();
   }
 }
 
 void LayerTreeHostImpl::AnimateTopControls(base::TimeTicks time) {
   if (!top_controls_manager_ || !top_controls_manager_->animation())
     return;
   gfx::Vector2dF scroll = top_controls_manager_->Animate(time);
   if (active_tree_->TotalScrollOffset().y() == 0.f)
     return;
-  if (scroll.IsZero()) {
-    // This may happen on the first animation step. Force redraw otherwise
-    // the animation would stop because of no new frames.
-    SetNeedsRedraw();
-  } else {
+  if (!scroll.IsZero()) {
     ScrollViewportBy(gfx::ScaleVector2d(
         scroll, 1.f / active_tree_->total_page_scale_factor()));
+    SetNeedsRedraw();
   }
+  SetNeedsAnimate();
 }
 
 void LayerTreeHostImpl::AnimateLayers(base::TimeTicks monotonic_time) {
   if (!settings_.accelerated_animation_enabled ||
       !needs_animate_layers() ||
       !active_tree_->root_layer())
     return;
 
   TRACE_EVENT0("cc", "LayerTreeHostImpl::AnimateLayers");
 
   // TODO(ajuma): http://crbug.com/178171 - Animations use double for monotonic
   // time.
   double monotonic_time_for_cc_animations =
       (monotonic_time - base::TimeTicks()).InSecondsF();
   AnimationRegistrar::AnimationControllerMap copy =
       animation_registrar_->active_animation_controllers();
   for (AnimationRegistrar::AnimationControllerMap::iterator iter = copy.begin();
        iter != copy.end();
        ++iter)
     (*iter).second->Animate(monotonic_time_for_cc_animations);
 
-  SetNeedsRedraw();
+  SetNeedsAnimate();
 }
 
 void LayerTreeHostImpl::UpdateAnimationState(bool start_ready_animations) {
   if (!settings_.accelerated_animation_enabled ||
       !needs_animate_layers() ||
       !active_tree_->root_layer())
     return;
 
   TRACE_EVENT0("cc", "LayerTreeHostImpl::UpdateAnimationState");
   scoped_ptr<AnimationEventsVector> events =
       make_scoped_ptr(new AnimationEventsVector);
   AnimationRegistrar::AnimationControllerMap copy =
       animation_registrar_->active_animation_controllers();
   for (AnimationRegistrar::AnimationControllerMap::iterator iter = copy.begin();
        iter != copy.end();
        ++iter)
     (*iter).second->UpdateState(start_ready_animations, events.get());
 
   if (!events->empty()) {
     client_->PostAnimationEventsToMainThreadOnImplThread(events.Pass());
   }
+
+  SetNeedsAnimate();
 }
 
 base::TimeDelta LayerTreeHostImpl::LowFrequencyAnimationInterval() const {
   return base::TimeDelta::FromSeconds(1);
 }
 
 void LayerTreeHostImpl::SendReleaseResourcesRecursive(LayerImpl* current) {
   DCHECK(current);
   current->ReleaseResources();
   if (current->mask_layer())
@@ skipping 53 matching lines @@
 
 void LayerTreeHostImpl::AnimateScrollbarsRecursive(LayerImpl* layer,
                                                    base::TimeTicks time) {
   if (!layer)
     return;
 
   ScrollbarAnimationController* scrollbar_controller =
       layer->scrollbar_animation_controller();
   if (scrollbar_controller && scrollbar_controller->Animate(time)) {
     TRACE_EVENT_INSTANT0(
-        "cc", "LayerTreeHostImpl::SetNeedsRedraw due to AnimateScrollbars",
+        "cc",
+        "LayerTreeHostImpl::SetNeedsAnimate due to AnimateScrollbars",
         TRACE_EVENT_SCOPE_THREAD);
-    SetNeedsRedraw();
+    SetNeedsAnimate();
   }
 
   for (size_t i = 0; i < layer->children().size(); ++i)
     AnimateScrollbarsRecursive(layer->children()[i], time);
 }
 
 void LayerTreeHostImpl::StartScrollbarAnimation() {
   TRACE_EVENT0("cc", "LayerTreeHostImpl::StartScrollbarAnimation");
   StartScrollbarAnimationRecursive(RootLayer(), CurrentFrameTimeTicks());
 }
 
 void LayerTreeHostImpl::StartScrollbarAnimationRecursive(LayerImpl* layer,
                                                          base::TimeTicks time) {
   if (!layer)
     return;
 
   ScrollbarAnimationController* scrollbar_controller =
       layer->scrollbar_animation_controller();
   if (scrollbar_controller && scrollbar_controller->IsAnimating()) {
     base::TimeDelta delay = scrollbar_controller->DelayBeforeStart(time);
-    if (delay > base::TimeDelta())
+    if (delay > base::TimeDelta()) {
       client_->RequestScrollbarAnimationOnImplThread(delay);
-    else if (scrollbar_controller->Animate(time))
-      SetNeedsRedraw();
+    } else if (scrollbar_controller->Animate(time)) {
+      SetNeedsAnimate();
+    }
   }
 
   for (size_t i = 0; i < layer->children().size(); ++i)
     StartScrollbarAnimationRecursive(layer->children()[i], time);
 }
 
 void LayerTreeHostImpl::SetTreePriority(TreePriority priority) {
   if (!tile_manager_)
     return;
 
@@ skipping 170 matching lines @@
   swap_promise_monitor_.erase(monitor);
 }
 
 void LayerTreeHostImpl::NotifySwapPromiseMonitorsOfSetNeedsRedraw() {
   std::set<SwapPromiseMonitor*>::iterator it = swap_promise_monitor_.begin();
   for (; it != swap_promise_monitor_.end(); it++)
     (*it)->OnSetNeedsRedrawOnImpl();
 }
 
 }  // namespace cc