Compat CTS: tidy readbackFromWebGPUCanvas issues.

Bug: dawn:2187
Change-Id: I7c9ea8a5760067871e4f8ed560c0ada036afb049
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/160221
Kokoro: Stephen White <senorblanco@chromium.org>
Bot-Commit: rubber-stamper@appspot.gserviceaccount.com <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Stephen White <senorblanco@chromium.org>
diff --git a/webgpu-cts/compat-expectations.txt b/webgpu-cts/compat-expectations.txt
index 36fcd0f..b4bddbd 100644
--- a/webgpu-cts/compat-expectations.txt
+++ b/webgpu-cts/compat-expectations.txt
@@ -148,18 +148,24 @@
 crbug.com/dawn/2076 webgpu:api,operation,rendering,depth_bias:depth_bias:quadAngle=0;bias=8388608;biasSlopeScale=0;biasClamp=0.125 [ Failure ]
 crbug.com/dawn/2076 webgpu:api,operation,rendering,depth_bias:depth_bias_24bit_format:format="depth24plus";quadAngle=0;bias=8388608;biasSlopeScale=0;biasClamp=0.1 [ Failure ]
 crbug.com/dawn/2076 webgpu:api,operation,rendering,depth_bias:depth_bias_24bit_format:format="depth24plus-stencil8";quadAngle=0;bias=8388608;biasSlopeScale=0;biasClamp=0.1 [ Failure ]
-crbug.com/dawn/2076 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="bgra8unorm";alphaMode="opaque";colorSpace="display-p3";webgpuCanvasType="offscreen";canvas2DType="offscreen" [ Failure ]
-crbug.com/dawn/2076 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="bgra8unorm";alphaMode="opaque";colorSpace="display-p3";webgpuCanvasType="offscreen";canvas2DType="onscreen" [ Failure ]
-crbug.com/dawn/2076 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="bgra8unorm";alphaMode="opaque";colorSpace="display-p3";webgpuCanvasType="onscreen";canvas2DType="offscreen" [ Failure ]
-crbug.com/dawn/2076 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="bgra8unorm";alphaMode="opaque";colorSpace="display-p3";webgpuCanvasType="onscreen";canvas2DType="onscreen" [ Failure ]
-crbug.com/dawn/2076 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="rgba16float";alphaMode="opaque";colorSpace="display-p3";webgpuCanvasType="offscreen";canvas2DType="offscreen" [ Failure ]
-crbug.com/dawn/2076 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="rgba16float";alphaMode="opaque";colorSpace="display-p3";webgpuCanvasType="offscreen";canvas2DType="onscreen" [ Failure ]
-crbug.com/dawn/2076 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="rgba16float";alphaMode="opaque";colorSpace="display-p3";webgpuCanvasType="onscreen";canvas2DType="offscreen" [ Failure ]
-crbug.com/dawn/2076 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="rgba16float";alphaMode="opaque";colorSpace="display-p3";webgpuCanvasType="onscreen";canvas2DType="onscreen" [ Failure ]
-crbug.com/dawn/2076 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="rgba8unorm";alphaMode="opaque";colorSpace="display-p3";webgpuCanvasType="offscreen";canvas2DType="offscreen" [ Failure ]
-crbug.com/dawn/2076 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="rgba8unorm";alphaMode="opaque";colorSpace="display-p3";webgpuCanvasType="offscreen";canvas2DType="onscreen" [ Failure ]
-crbug.com/dawn/2076 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="rgba8unorm";alphaMode="opaque";colorSpace="display-p3";webgpuCanvasType="onscreen";canvas2DType="offscreen" [ Failure ]
-crbug.com/dawn/2076 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="rgba8unorm";alphaMode="opaque";colorSpace="display-p3";webgpuCanvasType="onscreen";canvas2DType="onscreen" [ Failure ]
+
+# readbackFromWebGPUCanvas: alphaMode="opaque" transferToImageBitmap issues, offscreenCanvas
+# WebGPUTextureAlphaClearer needs RenderAttachment internal texture usage
+crbug.com/dawn/2187 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="bgra8unorm";alphaMode="opaque";colorSpace="srgb";snapshotType="transferToImageBitmap" [ Failure ]
+crbug.com/dawn/2187 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba8unorm";alphaMode="opaque";colorSpace="srgb";snapshotType="transferToImageBitmap" [ Failure ]
+crbug.com/dawn/2187 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba8unorm";alphaMode="opaque";colorSpace="display-p3";snapshotType="transferToImageBitmap" [ Failure ]
+crbug.com/dawn/2187 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba16float";alphaMode="opaque";colorSpace="srgb";snapshotType="transferToImageBitmap" [ Failure ]
+crbug.com/dawn/2187 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba16float";alphaMode="opaque";colorSpace="display-p3";snapshotType="transferToImageBitmap" [ Failure ]
+crbug.com/dawn/2187 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="bgra8unorm";alphaMode="opaque";colorSpace="display-p3";snapshotType="transferToImageBitmap" [ Failure ]
+
+# readbackFromWebGPUCanvas: slight pixel differences with format="rgba16float" alphaMode="opaque" snapshotType="imageBitmap"
+crbug.com/dawn/2218 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:onscreenCanvas,snapshot:format="rgba16float";alphaMode="opaque";colorSpace="srgb";snapshotType="imageBitmap" [ Failure ]
+crbug.com/dawn/2218 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba16float";alphaMode="opaque";colorSpace="srgb";snapshotType="imageBitmap" [ Failure ]
+
+# readbackFromWebGPUCanvas: precision issues with colorSpace="display-p3" alphaMode="opaque"
+crbug.com/dawn/2219 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="bgra8unorm";alphaMode="opaque";colorSpace="display-p3";* [ Failure ]
+crbug.com/dawn/2219 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="rgba16float";alphaMode="opaque";colorSpace="display-p3";* [ Failure ]
+crbug.com/dawn/2219 webgpu:web_platform,canvas,readbackFromWebGPUCanvas:drawTo2DCanvas:format="rgba8unorm";alphaMode="opaque";colorSpace="display-p3";* [ Failure ]
 
 # View format reinterpretation is unsupported on OpenGLES
 crbug.com/dawn/1360 webgpu:api,operation,texture_view,format_reinterpretation:render_and_resolve_attachment:format="rgba8unorm";viewFormat="rgba8unorm-srgb";sampleCount=1 [ Failure ]
@@ -264,25 +270,6 @@
 crbug.com/dawn/2086 webgpu:web_platform,canvas,configure:usage:* [ Failure ]
 crbug.com/dawn/2086 webgpu:web_platform,canvas,configure:viewFormats:* [ Failure ]
 
-# Usage does not include Texture Binding
-[ intel-0x9bc5 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="bgra8unorm";alphaMode="opaque";colorSpace="display-p3";snapshotType="transferToImageBitmap" [ Failure ]
-[ nvidia-0x2184 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="bgra8unorm";alphaMode="opaque";colorSpace="display-p3";snapshotType="transferToImageBitmap" [ Failure ]
-[ intel-0x9bc5 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="bgra8unorm";alphaMode="opaque";colorSpace="srgb";snapshotType="transferToImageBitmap" [ Failure ]
-[ nvidia-0x2184 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="bgra8unorm";alphaMode="opaque";colorSpace="srgb";snapshotType="transferToImageBitmap" [ Failure ]
-[ intel-0x9bc5 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba16float";alphaMode="opaque";colorSpace="display-p3";snapshotType="transferToImageBitmap" [ Failure ]
-[ nvidia-0x2184 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba16float";alphaMode="opaque";colorSpace="display-p3";snapshotType="transferToImageBitmap" [ Failure ]
-[ nvidia-0x2184 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba16float";alphaMode="opaque";colorSpace="srgb";snapshotType="imageBitmap" [ Failure ]
-[ intel-0x9bc5 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba16float";alphaMode="opaque";colorSpace="srgb";snapshotType="transferToImageBitmap" [ Failure ]
-[ nvidia-0x2184 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba16float";alphaMode="opaque";colorSpace="srgb";snapshotType="transferToImageBitmap" [ Failure ]
-[ intel-0x9bc5 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba16float";alphaMode="premultiplied";colorSpace="srgb";snapshotType="imageBitmap" [ Failure ]
-[ intel-0x9bc5 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba16float";alphaMode="premultiplied";colorSpace="srgb";snapshotType="transferToImageBitmap" [ Failure ]
-[ intel-0x9bc5 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba8unorm";alphaMode="opaque";colorSpace="display-p3";snapshotType="transferToImageBitmap" [ Failure ]
-[ nvidia-0x2184 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba8unorm";alphaMode="opaque";colorSpace="display-p3";snapshotType="transferToImageBitmap" [ Failure ]
-[ intel-0x9bc5 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba8unorm";alphaMode="opaque";colorSpace="srgb";snapshotType="transferToImageBitmap" [ Failure ]
-[ nvidia-0x2184 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:offscreenCanvas,snapshot:format="rgba8unorm";alphaMode="opaque";colorSpace="srgb";snapshotType="transferToImageBitmap" [ Failure ]
-[ nvidia-0x2184 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:onscreenCanvas,snapshot:format="rgba16float";alphaMode="opaque";colorSpace="srgb";snapshotType="imageBitmap" [ Failure ]
-[ intel-0x9bc5 ] webgpu:web_platform,canvas,readbackFromWebGPUCanvas:onscreenCanvas,snapshot:format="rgba16float";alphaMode="premultiplied";colorSpace="srgb";snapshotType="imageBitmap" [ Failure ]
-
 # Memory Sync
 crbug.com/dawn/2083 [ intel-0x9bc5 ] webgpu:api,operation,memory_sync,buffer,multiple_buffers:ww:boundary="command-buffer";writeOps=["storage","t2b-copy"];contexts=["render-bundle-encoder","command-encoder"] [ Failure ]
 crbug.com/dawn/2083 [ intel-0x9bc5 ] webgpu:api,operation,memory_sync,buffer,multiple_buffers:ww:boundary="command-buffer";writeOps=["storage","t2b-copy"];contexts=["render-pass-encoder","command-encoder"] [ Failure ]