Reuse property trees

cc/trees/layer_tree_host.cc

Index: cc/trees/layer_tree_host.cc
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index 53bfcb8fc22d597432c2fbeefa1c6aedcc1501f8..01ca6994cae41b402ef13268305ab84a75093ad7 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -509,6 +509,8 @@ void LayerTreeHost::SetNeedsCommit() {
 
 void LayerTreeHost::SetNeedsFullTreeSync() {
   needs_full_tree_sync_ = true;
+
+  property_trees_.needs_rebuild = true;
   SetNeedsCommit();
 }
 
@@ -626,6 +628,7 @@ void LayerTreeHost::SetViewportSize(const gfx::Size& device_viewport_size) {
 
   device_viewport_size_ = device_viewport_size;
 
+  property_trees_.needs_rebuild = true;
   SetNeedsCommit();
 }
 
@@ -649,7 +652,10 @@ void LayerTreeHost::SetTopControlsShownRatio(float ratio) {
 
 void LayerTreeHost::ApplyPageScaleDeltaFromImplSide(float page_scale_delta) {
   DCHECK(CommitRequested());
+  if (page_scale_delta == 1.f)
+    return;
   page_scale_factor_ *= page_scale_delta;
+  property_trees_.needs_rebuild = true;
 }
 
 void LayerTreeHost::SetPageScaleFactorAndLimits(float page_scale_factor,
@@ -663,6 +669,7 @@ void LayerTreeHost::SetPageScaleFactorAndLimits(float page_scale_factor,
   page_scale_factor_ = page_scale_factor;
   min_page_scale_factor_ = min_page_scale_factor;
   max_page_scale_factor_ = max_page_scale_factor;
+  property_trees_.needs_rebuild = true;
   SetNeedsCommit();
 }
 
@@ -796,7 +803,6 @@ bool LayerTreeHost::UpdateLayers(Layer* root_layer,
     // that we won't be able to detect if a layer is part of |update_list|.
     // Change this if this information is required.
     int render_surface_layer_list_id = 0;
-    PropertyTrees property_trees;
     LayerTreeHostCommon::CalcDrawPropsMainInputs inputs(
         root_layer, device_viewport_size(), gfx::Transform(),
         device_scale_factor_, page_scale_factor_, page_scale_layer,
@@ -806,7 +812,7 @@ bool LayerTreeHost::UpdateLayers(Layer* root_layer,
         can_render_to_separate_surface,
         settings_.layer_transforms_should_scale_layer_contents,
         settings_.verify_property_trees, &update_list,
-        render_surface_layer_list_id, &property_trees);
+        render_surface_layer_list_id, &property_trees_);
     LayerTreeHostCommon::CalculateDrawProperties(&inputs);
   }
 
@@ -1119,6 +1125,7 @@ void LayerTreeHost::SetDeviceScaleFactor(float device_scale_factor) {
     return;
   device_scale_factor_ = device_scale_factor;
 
+  property_trees_.needs_rebuild = true;
   SetNeedsCommit();
 }
 
@@ -1139,8 +1146,12 @@ void LayerTreeHost::AnimateLayers(base::TimeTicks monotonic_time) {
   if (!settings_.accelerated_animation_enabled)
     return;
 
-  if (animation_registrar_->AnimateLayers(monotonic_time))
-    animation_registrar_->UpdateAnimationState(true, NULL);
+  AnimationEventsVector events;
+  if (animation_registrar_->AnimateLayers(monotonic_time)) {
+    animation_registrar_->UpdateAnimationState(true, &events);
+    if (!events.empty())
+      property_trees_.needs_rebuild = true;
+  }
 }
 
 UIResourceId LayerTreeHost::CreateUIResource(UIResourceClient* client) {