WebGPU: Add GPUBindingType "multisampled-texture".

And deprecate GPUBindGroupLayoutEntry.multisampled.

Bug: dawn:517
Change-Id: I0959d46f603c2c7741dc2288098ca119d38b344e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2440655Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#812603}

third_party/blink/renderer/modules/webgpu/dawn_conversions.cc

@@ -39,6 +39,9 @@ WGPUBindingType AsDawnEnum<WGPUBindingType>(const WTF::String& webgpu_enum) {
   if (webgpu_enum == "sampled-texture") {
     return WGPUBindingType_SampledTexture;
   }
+  if (webgpu_enum == "multisampled-texture") {
+    return WGPUBindingType_MultisampledTexture;
+  }
   if (webgpu_enum == "readonly-storage-texture") {
     return WGPUBindingType_ReadonlyStorageTexture;
   }

third_party/blink/renderer/modules/webgpu/gpu_bind_group_layout.cc

@@ -36,6 +36,12 @@ WGPUBindGroupLayoutEntry AsDawnType(
       webgpu_binding->textureComponentType());
   dawn_binding.multisampled = webgpu_binding->multisampled();
 
+  if (dawn_binding.multisampled) {
+    device->AddConsoleWarning(
+        "Creating a GPUBindGroupLayoutEntry with entry.multisampled = true is "
+        "deprecated: set entry.type = \"multisampled-texture\" instead.");
+  }
+
   dawn_binding.storageTextureFormat =
       AsDawnEnum<WGPUTextureFormat>(webgpu_binding->storageTextureFormat());
 

third_party/blink/renderer/modules/webgpu/gpu_bind_group_layout_entry.idl

@@ -28,6 +28,7 @@ enum GPUBindingType {
     "sampler",
     "comparison-sampler",
     "sampled-texture",
+    "multisampled-texture",
     "readonly-storage-texture",
     "writeonly-storage-texture",
 };