If you run the layout tests on a Retina MacBook Pro (or any Mac simulating HiDPI mode), many canvas tests fail. There were many intentional changes made to canvas for a HiDPI environment, so these failures are not necessarily bugs, but they will probably have to be investigated individually to determine that. At a high level, we need to decide if we want to have a new directory like the platform directory for test results that are specific to different deviceScaleFactors. Or perhaps tests can change to accommodate evaluating results for each platform. A directory would be a nice short-term solution. Anyway, these are all of the canvas tests that I see failing: canvas/philip/tests/2d.imageData.get.order.cols.html canvas/philip/tests/2d.imageData.get.order.rows.html canvas/philip/tests/2d.imageData.put.unchanged.html canvas/philip/tests/2d.text.draw.baseline.ideographic.html fast/canvas/2d.backingStorePixelRatio.html fast/canvas/canvas-alphaImageData-behavior.html fast/canvas/canvas-copyPixels.html fast/canvas/canvas-fillPath-shadow.html fast/canvas/canvas-getImageData-negative-source.html fast/canvas/canvas-lineWidth-intact-after-strokeRect.html fast/canvas/canvas-scale-strokePath-shadow.html fast/canvas/canvas-state-intact-after-putImageData.html fast/canvas/canvas-strokePath-cap-join.html fast/canvas/canvas-strokePath-gradient-shadow.html fast/canvas/canvas-strokeRect-alpha-shadow.html fast/canvas/canvas-strokeRect-gradient-shadow.html fast/canvas/canvas-style-intact-after-text.html fast/canvas/webgl/gl-pixelstorei.html fast/canvas/webgl/tex-image-and-sub-image-2d-with-canvas-rgb565.html fast/canvas/webgl/tex-image-and-sub-image-2d-with-canvas-rgba4444.html fast/canvas/webgl/tex-image-and-sub-image-2d-with-canvas-rgba5551.html fast/canvas/webgl/tex-image-and-sub-image-2d-with-canvas.html fast/canvas/webgl/tex-image-and-sub-image-2d-with-image-rgb565.html fast/canvas/webgl/tex-image-and-sub-image-2d-with-image-rgba4444.html fast/canvas/webgl/tex-image-and-sub-image-2d-with-image-rgba5551.html fast/canvas/webgl/tex-image-and-sub-image-2d-with-image.html