Retain tray bubble's rounded corners when the bubble animates out

ui/compositor/layer.cc

Index: ui/compositor/layer.cc
diff --git a/ui/compositor/layer.cc b/ui/compositor/layer.cc
index 2da468a5b48ca5f69c8ebe98ead61cfa42ba8b11..dd1900964658b720836d31986a7247d07f982b85 100644
--- a/ui/compositor/layer.cc
+++ b/ui/compositor/layer.cc
@@ -56,8 +56,6 @@ Layer::Layer()
       layer_brightness_(0.0f),
       layer_grayscale_(0.0f),
       layer_inverted_(false),
-      layer_mask_(NULL),
-      layer_mask_back_link_(NULL),
       zoom_(1),
       zoom_inset_(0),
       delegate_(NULL),
@@ -80,8 +78,6 @@ Layer::Layer(LayerType type)
       layer_brightness_(0.0f),
       layer_grayscale_(0.0f),
       layer_inverted_(false),
-      layer_mask_(NULL),
-      layer_mask_back_link_(NULL),
       zoom_(1),
       zoom_inset_(0),
       delegate_(NULL),
@@ -102,12 +98,10 @@ Layer::~Layer() {
     compositor_->SetRootLayer(NULL);
   if (parent_)
     parent_->Remove(this);
-  if (layer_mask_)
-    SetMaskLayer(NULL);
-  if (layer_mask_back_link_)
-    layer_mask_back_link_->SetMaskLayer(NULL);
   for (size_t i = 0; i < children_.size(); ++i)
     children_[i]->parent_ = NULL;
+  if (layer_mask_.get())
+    cc_layer_->SetMaskLayer(NULL);

[michaelpg, 2013/10/04 05:56:41]

in lieu of calling SetMaskLayer with an empty scoped_ptr<Layer>

   cc_layer_->RemoveLayerAnimationEventObserver(this);
   cc_layer_->RemoveFromParent();
 }
@@ -280,28 +274,19 @@ void Layer::SetLayerInverted(bool inverted) {
   SetLayerFilters();
 }
 
-void Layer::SetMaskLayer(Layer* layer_mask) {
+void Layer::SetMaskLayer(scoped_ptr<Layer> layer_mask) {
   // The provided mask should not have a layer mask itself.
-  DCHECK(!layer_mask ||
+  DCHECK(!layer_mask.get() ||
          (!layer_mask->layer_mask_layer() &&
-          layer_mask->children().empty() &&
-          !layer_mask->layer_mask_back_link_));
-  DCHECK(!layer_mask_back_link_);
-  if (layer_mask_ == layer_mask)
-    return;
-  // We need to de-reference the currently linked object so that no problem
-  // arises if the mask layer gets deleted before this object.
-  if (layer_mask_)
-    layer_mask_->layer_mask_back_link_ = NULL;
-  layer_mask_ = layer_mask;
+          layer_mask->children().empty()));
+
   cc_layer_->SetMaskLayer(
-      layer_mask ? layer_mask->cc_layer() : NULL);
-  // We need to reference the linked object so that it can properly break the
-  // link to us when it gets deleted.
-  if (layer_mask) {
-    layer_mask->layer_mask_back_link_ = this;
+      layer_mask.get() ? layer_mask->cc_layer() : NULL);
+
+  if (layer_mask)
     layer_mask->OnDeviceScaleFactorChanged(device_scale_factor_);
-  }
+
+  layer_mask_.reset(layer_mask.release());

[michaelpg, 2013/10/04 05:56:41]

layer_mask is a scoped_ptr that now owns the layer, so we have to transfer that
ownership to the layer_mask_ member variable... is there a cleaner way to do
this?

If not, should I use layer_mask.Pass() instead of release()? Digging through
scoped_ptr and move.h seems to indicate that this will ultimately call swap()
thus transferring ownership to layer_mask_.

[piman, 2013/10/04 18:05:33]

Yes, layer_mask_ = layer_mask.Pass(); is more idiomatic.

[michaelpg, 2013/12/10 02:04:03]

Ok, thanks.

 }
 
 void Layer::SetBackgroundZoom(float zoom, int inset) {
@@ -623,7 +608,7 @@ void Layer::OnDeviceScaleFactorChanged(float device_scale_factor) {
     delegate_->OnDeviceScaleFactorChanged(device_scale_factor);
   for (size_t i = 0; i < children_.size(); ++i)
     children_[i]->OnDeviceScaleFactorChanged(device_scale_factor);
-  if (layer_mask_)
+  if (layer_mask_.get())
     layer_mask_->OnDeviceScaleFactorChanged(device_scale_factor);
 }