Thread ui transform animations

ui/compositor/layer.cc

Index: ui/compositor/layer.cc
diff --git a/ui/compositor/layer.cc b/ui/compositor/layer.cc
index b73419a2992adbb9d1ffed37fa47e3b26b48aba6..f2499ae42437789a244ab1bafd571bc84ad2f9b5 100644
--- a/ui/compositor/layer.cc
+++ b/ui/compositor/layer.cc
@@ -200,7 +200,7 @@ gfx::Transform Layer::GetTargetTransform() const {
       LayerAnimationElement::TRANSFORM)) {
     return animator_->GetTargetTransform();
   }
-  return transform_;
+  return transform();
 }
 
 void Layer::SetBounds(const gfx::Rect& bounds) {
@@ -410,6 +410,19 @@ void Layer::ConvertPointToLayer(const Layer* source,
     target->ConvertPointFromAncestor(root_layer, point);
 }
 
+// static
+gfx::Transform Layer::ConvertTransformToCCTransform(
+    const gfx::Transform& transform,
+    const gfx::Rect& bounds,
+    float device_scale_factor) {
+  gfx::Transform cc_transform;
+  cc_transform.Scale(device_scale_factor, device_scale_factor);
+  cc_transform.Translate(bounds.x(), bounds.y());
+  cc_transform.PreconcatTransform(transform);
+  cc_transform.Scale(1.0f / device_scale_factor, 1.0f / device_scale_factor);
+  return cc_transform;
+}
+
 void Layer::SetFillsBoundsOpaquely(bool fills_bounds_opaquely) {
   if (fills_bounds_opaquely_ == fills_bounds_opaquely)
     return;
@@ -449,6 +462,7 @@ void Layer::SetExternalTexture(Texture* texture) {
     }
     cc_layer_->removeLayerAnimationEventObserver(this);
     new_layer->setOpacity(cc_layer_->opacity());
+    new_layer->setTransform(cc_layer_->transform());
     cc_layer_= new_layer;
     cc_layer_->addLayerAnimationEventObserver(this);
     cc_layer_is_accelerated_ = layer_updated_externally_;
@@ -460,7 +474,6 @@ void Layer::SetExternalTexture(Texture* texture) {
     cc_layer_->setContentsOpaque(fills_bounds_opaquely_);
     cc_layer_->setForceRenderSurface(force_render_surface_);
     cc_layer_->setIsDrawable(IsDrawn());
-    RecomputeTransform();
   }
   RecomputeDrawsContentAndUVRect();
 }
@@ -519,8 +532,11 @@ void Layer::SuppressPaint() {
 void Layer::OnDeviceScaleFactorChanged(float device_scale_factor) {
   if (device_scale_factor_ == device_scale_factor)
     return;
+  if (animator_)
+    animator_->StopAnimatingProperty(LayerAnimationElement::TRANSFORM);
+  gfx::Transform transform = this->transform();
   device_scale_factor_ = device_scale_factor;
-  RecomputeTransform();
+  RecomputeCCTransformFromTransform(transform);
   RecomputeDrawsContentAndUVRect();
   SchedulePaint(gfx::Rect(bounds_.size()));
   if (delegate_)
@@ -641,9 +657,10 @@ void Layer::SetBoundsImmediately(const gfx::Rect& bounds) {
   if (delegate_)
     closure = delegate_->PrepareForLayerBoundsChange();
   bool was_move = bounds_.size() == bounds.size();
+  gfx::Transform transform = this->transform();
   bounds_ = bounds;
 
-  RecomputeTransform();
+  RecomputeCCTransformFromTransform(transform);
   RecomputeDrawsContentAndUVRect();
   if (!closure.is_null())
     closure.Run();
@@ -660,9 +677,7 @@ void Layer::SetBoundsImmediately(const gfx::Rect& bounds) {
 }
 
 void Layer::SetTransformImmediately(const gfx::Transform& transform) {
-  transform_ = transform;
-
-  RecomputeTransform();
+  RecomputeCCTransformFromTransform(transform);
 }
 
 void Layer::SetOpacityImmediately(float opacity) {
@@ -731,7 +746,7 @@ const gfx::Rect& Layer::GetBoundsForAnimation() const {
   return bounds();
 }
 
-const gfx::Transform& Layer::GetTransformForAnimation() const {
+gfx::Transform Layer::GetTransformForAnimation() const {
   return transform();
 }
 
@@ -759,6 +774,10 @@ SkColor Layer::GetColorForAnimation() const {
       solid_color_layer_->backgroundColor() : SK_ColorBLACK;
 }
 
+float Layer::GetDeviceScaleFactor() const {
+  return device_scale_factor_;
+}
+
 void Layer::AddThreadedAnimation(scoped_ptr<cc::Animation> animation) {
   DCHECK(cc_layer_);
   cc_layer_->addAnimation(animation.Pass());
@@ -784,22 +803,19 @@ void Layer::CreateWebLayer() {
   cc_layer_->addLayerAnimationEventObserver(this);
 }
 
-void Layer::RecomputeTransform() {
-  gfx::Transform scale_translate;
-  scale_translate.matrix().set3x3(device_scale_factor_, 0, 0,
-                                  0, device_scale_factor_, 0,
-                                  0, 0, 1);
-  // Start with the inverse matrix of above.
+void Layer::RecomputeCCTransformFromTransform(const gfx::Transform& transform) {
+  cc_layer_->setTransform(ConvertTransformToCCTransform(transform,
+                                                        bounds_,
+                                                        device_scale_factor_));
+}
+
+gfx::Transform Layer::transform() const {
   gfx::Transform transform;
-  transform.matrix().set3x3(1.0f / device_scale_factor_, 0, 0,
-                            0, 1.0f / device_scale_factor_, 0,
-                            0, 0, 1);
-  transform.ConcatTransform(transform_);
-  gfx::Transform translate;
-  translate.Translate(bounds_.x(), bounds_.y());
-  transform.ConcatTransform(translate);
-  transform.ConcatTransform(scale_translate);
-  cc_layer_->setTransform(transform);
+  transform.Translate(-bounds_.x(), -bounds_.y());
+  transform.Scale(1.0f / device_scale_factor_, 1.0f / device_scale_factor_);
+  transform.PreconcatTransform(cc_layer_->transform());
+  transform.Scale(device_scale_factor_, device_scale_factor_);
+  return transform;
 }
 
 void Layer::RecomputeDrawsContentAndUVRect() {