Suppress tests failing with Metal backend validation layers

Bug: dawn:1430
Change-Id: Id8fad88bd5014a2a90e0d580d9df6831dd507b5d
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/113500
Reviewed-by: Gregg Tavares <gman@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Auto-Submit: Austin Eng <enga@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
diff --git a/webgpu-cts/expectations.txt b/webgpu-cts/expectations.txt
index 9060751..0199c56 100644
--- a/webgpu-cts/expectations.txt
+++ b/webgpu-cts/expectations.txt
@@ -126,6 +126,12 @@
 crbug.com/dawn/1107 [ intel mac ] webgpu:api,operation,command_buffer,copyTextureToTexture:color_textures,non_compressed,non_array:srcFormat="rgba32float";dstFormat="rgba32float";dimension="2d" [ Failure ]
 
 ################################################################################
+# Failing with Metal validation layers
+################################################################################
+crbug.com/dawn/1430 [ mac dawn-backend-validation ] webgpu:api,operation,command_buffer,image_copy:rowsPerImage_and_bytesPerRow:initMethod="CopyB2T";checkMethod="FullCopyT2B";* [ Failure ]
+crbug.com/dawn/1430 [ mac dawn-backend-validation ] webgpu:api,operation,command_buffer,image_copy:rowsPerImage_and_bytesPerRow:initMethod="WriteTexture";checkMethod="PartialCopyT2B";* [ Failure ]
+
+################################################################################
 # Large and slow tests
 # KEEP
 ################################################################################