Roll Dawn from 413dcf8a40df to b6c0dac11024 (6 revisions)

https://dawn.googlesource.com/dawn.git/+log/413dcf8a40df..b6c0dac11024

2021-04-17 dawn-autoroll@skia-public.iam.gserviceaccount.com Roll Tint from fe70c75bc573 to 4649377d0575 (10 revisions)
2021-04-17 bajones@chromium.org Deprecate renderpass color/depth .attachment
2021-04-16 jrprice@google.com Enable WGSLUnsortedStructIO test
2021-04-16 jrprice@google.com Revert "Temporarily stop running tests on D3D12 with use_tint_generator"
2021-04-16 dawn-autoroll@skia-public.iam.gserviceaccount.com Roll Tint from cc46e393e481 to fe70c75bc573 (19 revisions)
2021-04-16 enga@chromium.org Add default to VertexState.bufferCount

Also rolling transitive DEPS:
  https://dawn.googlesource.com/tint from cc46e393e481 to 4649377d0575

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/dawn-skia-autoroll
Please CC alanbaker@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/master/autoroll/README.md

Cq-Include-Trybots: skia/skia.primary:Build-Debian10-Clang-x86_64-Debug-Dawn
Bug: None
Tbr: alanbaker@google.com
Change-Id: Ica6872ca088498ff7f7f6a4307720a696d228d79
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/397842
Reviewed-by: skia-autoroll <skia-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: skia-autoroll <skia-autoroll@skia-public.iam.gserviceaccount.com>
diff --git a/DEPS b/DEPS
index 39d95f1..6af7ab7 100644
--- a/DEPS
+++ b/DEPS
@@ -17,10 +17,10 @@
   "third_party/externals/d3d12allocator"  : "https://skia.googlesource.com/external/github.com/GPUOpen-LibrariesAndSDKs/D3D12MemoryAllocator.git@169895d529dfce00390a20e69c2f516066fe7a3b",
   # Dawn requires jinja2 and markupsafe for the code generator, and tint for SPIRV compilation.
   # When the Dawn revision is updated these should be updated from the Dawn DEPS as well.
-  "third_party/externals/dawn"            : "https://dawn.googlesource.com/dawn.git@413dcf8a40df9db9cf51ec828c1e0331251ef0d7",
+  "third_party/externals/dawn"            : "https://dawn.googlesource.com/dawn.git@b6c0dac11024031a46051e74cf67df07061babcc",
   "third_party/externals/jinja2"          : "https://chromium.googlesource.com/chromium/src/third_party/jinja2@a82a4944a7f2496639f34a89c9923be5908b80aa",
   "third_party/externals/markupsafe"      : "https://chromium.googlesource.com/chromium/src/third_party/markupsafe@0944e71f4b2cb9a871bcbe353f95e889b64a611a",
-  "third_party/externals/tint"            : "https://dawn.googlesource.com/tint@cc46e393e481482853f737f102516346db236054",
+  "third_party/externals/tint"            : "https://dawn.googlesource.com/tint@4649377d0575a0ae8c314ee6235fa0cd55413e22",
   "third_party/externals/dng_sdk"         : "https://android.googlesource.com/platform/external/dng_sdk.git@c8d0c9b1d16bfda56f15165d39e0ffa360a11123",
   "third_party/externals/egl-registry"    : "https://skia.googlesource.com/external/github.com/KhronosGroup/EGL-Registry@a0bca08de07c7d7651047bedc0b653cfaaa4f2ae",
   "third_party/externals/expat"           : "https://chromium.googlesource.com/external/github.com/libexpat/libexpat.git@e976867fb57a0cd87e3b0fe05d59e0ed63c6febb",