Remove UnsafeAPI toggle for readonly depth/stencil attachment

Readonly depth/stencil attachment has already been supported on
D3D12, Metal and Vulkan. Its implement on GL and GLES will be
at post V1 via WebGPU-compat.

Bug: dawn:485
Change-Id: I1c13232f405b10b36f66c1c452449a864ca8fedc
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/78441
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Yunchao He <yunchao.he@intel.com>
diff --git a/src/dawn_native/CommandEncoder.cpp b/src/dawn_native/CommandEncoder.cpp
index 0001555..def1f4e 100644
--- a/src/dawn_native/CommandEncoder.cpp
+++ b/src/dawn_native/CommandEncoder.cpp
@@ -654,13 +654,6 @@
                         descriptor->depthStencilAttachment->stencilReadOnly;
 
                     if (IsReadOnlyDepthStencilAttachment(descriptor->depthStencilAttachment)) {
-                        // TODO(dawn:485): Readonly depth/stencil attachment is not fully
-                        // implemented. Disallow it as unsafe until the implementaion is completed.
-                        DAWN_INVALID_IF(
-                            device->IsToggleEnabled(Toggle::DisallowUnsafeAPIs),
-                            "Readonly depth/stencil attachment is disallowed because it's not "
-                            "fully implemented");
-
                         usageTracker.TextureViewUsedAs(view, kReadOnlyRenderAttachment);
                     } else {
                         usageTracker.TextureViewUsedAs(view, wgpu::TextureUsage::RenderAttachment);