I was wondering if WebGL is considered stable enough to be enabled by default. It makes some PDFs render much faster and it has been off by default for a while now, so we have had quite some time to test it.

If we decide to enable WebGL by default, we should not forget to update https://github.com/mozilla/pdf.js/blob/master/extensions/chromium/preferences_schema.json#L39 as well.

/cc @yurydelendik 
/cc @Snuffleupagus (because IIRC you were testing WebGL too)

constructor() {
    
    this.alphaIsShape = false;
    this.fontSize = 0;
    this.fontSizeScale = 1;
    this.textMatrix = IDENTITY_MATRIX;
    this.textMatrixScale = 1;
    this.fontMatrix = FONT_IDENTITY_MATRIX;
    this.leading = 0;
    
    this.x = 0;
    this.y = 0;
    
    this.lineX = 0;
    this.lineY = 0;
    
    this.charSpacing = 0;
    this.wordSpacing = 0;
    this.textHScale = 1;
    this.textRenderingMode = TextRenderingMode.FILL;
    this.textRise = 0;