Rename ol.source.BingMapsOptions style property to imagerySet
Fire precompose events from map
ol.render.Event take an ol.webgl.Context object
Fire pre and postcompose events from webgl layers
Fire pre and postcompose events from webgl map
Rename arrayBuffer_ to renderArrayBuffer_
fixup! Fire pre and postcompose events from webgl layers
Move arrayBuffer_ to layer renderer
Set stencil to true in webgl context
Add a WebGL layer clipping example