@manoldonev Can you take a look at this? I couldn't find a scenario where there are significant performance gains (the projects mentioned had a different bug), but I think it's good even if only as a refactoring.

I'm working in allowing some layout properties to cascade from ProxyViewContainer to the children, so this breaking change will potentially make it impossible to implement something like CSS Grid. Can this breaking change be clarified or maybe worked around?

The main issue turned out to be elsewhere, so this PR can be reduced to only get the attribute selectors match their web counterparts.

@edusperoni Can you elaborate on your concern about the ProxyViewContainer change? Until now we have not actually considered setting css classes on ProxyViewContainer as a meaningful supported scenario. Are you actually trying to set such css classes or you are concerned that cascading will not work? Based on the current change I think cascading should continue to work?

@manoldonev Please see the discussion in NativeScript/nativescript-angular#1422 (comment)

My current plan is, once we settle on the implementation details of forwarding properties to children, to do:

<GridLayout class="grid-container">
  <my-component class="grid-header"></my-component>
  <my-component class="grid-left"></my-component>
  <my-component class="grid-content"></my-component>
  <my-component class="grid-footer"></my-component>
</GridLayout>

.grid-container {
   grid-template-areas: 'header header' 'left content' 'footer footer';
}

.grid-header {
   grid-area: header;
}
.grid-left {
   grid-area: left;
}
.grid-content {
   grid-area: content;
}
.grid-footer {
   grid-area: footer;
}

GridLayout would then take the children styles and apply row/col to them as required. If we remove the ability for ProxyViewContainer to be matched and properly hold styles, we'll no longer be able to implement grid or add properties that will be forwarded to children (like row/col) in CSS