diff --git a/spec/index.bs b/spec/index.bs
index 9cc87d6bbe..e29382ba8e 100644
--- a/spec/index.bs
+++ b/spec/index.bs
@@ -41,6 +41,14 @@ dictionary GPUExtent3D {
     required u32 height;
     required u32 depth;
 };
+
+interface GPUObjectBase {
+    DOMString? label;
+};
+
+dictionary GPUObjectDescriptorBase {
+    DOMString? label;
+};
 </script>
 
 Buffers {#buffers}
@@ -61,12 +69,12 @@ interface GPUBufferUsage {
     const u32 STORAGE = 128;
 };
 
-dictionary GPUBufferDescriptor {
+dictionary GPUBufferDescriptor : GPUObjectDescriptorBase {
     required u64 size;
     required GPUBufferUsageFlags usage;
 };
 
-interface GPUBuffer {
+interface GPUBuffer : GPUObjectBase {
     Promise<ArrayBuffer> mapReadAsync();
     Promise<ArrayBuffer> mapWriteAsync();
     void unmap();
@@ -167,7 +175,7 @@ interface GPUTextureUsage {
     const u32 OUTPUT_ATTACHMENT = 16;
 };
 
-dictionary GPUTextureDescriptor {
+dictionary GPUTextureDescriptor : GPUObjectDescriptorBase {
     required GPUExtent3D size;
     u32 arrayLayerCount = 1;
     u32 mipLevelCount = 1;
@@ -193,7 +201,7 @@ enum GPUTextureAspect {
     "depth-only"
 };
 
-dictionary GPUTextureViewDescriptor {
+dictionary GPUTextureViewDescriptor : GPUObjectDescriptorBase {
     required GPUTextureFormat format;
     required GPUTextureViewDimension dimension;
     required GPUTextureAspect aspect;
@@ -203,10 +211,10 @@ dictionary GPUTextureViewDescriptor {
     u32 arrayLayerCount = 1;
 };
 
-interface GPUTextureView {
+interface GPUTextureView : GPUObjectBase {
 };
 
-interface GPUTexture {
+interface GPUTexture : GPUObjectBase {
     GPUTextureView createView(GPUTextureViewDescriptor desc);
     GPUTextureView createDefaultView();
 
@@ -240,7 +248,7 @@ enum GPUCompareFunction {
     "always"
 };
 
-dictionary GPUSamplerDescriptor {
+dictionary GPUSamplerDescriptor : GPUObjectDescriptorBase {
     GPUAddressMode addressModeU = "clamp-to-edge";
     GPUAddressMode addressModeV = "clamp-to-edge";
     GPUAddressMode addressModeW = "clamp-to-edge";
@@ -252,7 +260,7 @@ dictionary GPUSamplerDescriptor {
     GPUCompareFunction compareFunction = "never";
 };
 
-interface GPUSampler {
+interface GPUSampler : GPUObjectBase {
 };
 </script>
 
@@ -285,18 +293,18 @@ dictionary GPUBindGroupLayoutBinding {
     required GPUBindingType type;
 };
 
-dictionary GPUBindGroupLayoutDescriptor {
+dictionary GPUBindGroupLayoutDescriptor : GPUObjectDescriptorBase {
     required sequence<GPUBindGroupLayoutBinding> bindings;
 };
 
-interface GPUBindGroupLayout {
+interface GPUBindGroupLayout : GPUObjectBase {
 };
 
-dictionary GPUPipelineLayoutDescriptor {
+dictionary GPUPipelineLayoutDescriptor : GPUObjectDescriptorBase {
     required sequence<GPUBindGroupLayout> bindGroupLayouts;
 };
 
-interface GPUPipelineLayout {
+interface GPUPipelineLayout : GPUObjectBase {
 };
 
 dictionary GPUBufferBinding {
@@ -312,12 +320,12 @@ dictionary GPUBindGroupBinding {
     required GPUBindingResource resource;
 };
 
-dictionary GPUBindGroupDescriptor {
+dictionary GPUBindGroupDescriptor : GPUObjectDescriptorBase {
     required GPUBindGroupLayout layout;
     required sequence<GPUBindGroupBinding> bindings;
 };
 
-interface GPUBindGroup {
+interface GPUBindGroup : GPUObjectBase {
 };
 </script>
 
@@ -330,11 +338,11 @@ Shader Module {#shader}
 // text and binary input.
 typedef (ArrayBuffer or DOMString) ArrayBufferOrDOMString;
 
-dictionary GPUShaderModuleDescriptor {
+dictionary GPUShaderModuleDescriptor : GPUObjectDescriptorBase {
     required ArrayBufferOrDOMString code;
 };
 
-interface GPUShaderModule {
+interface GPUShaderModule : GPUObjectBase {
 };
 </script>
 
@@ -531,7 +539,7 @@ dictionary GPUPipelineStageDescriptor {
     // TODO other stuff like specialization constants?
 };
 
-dictionary GPUPipelineDescriptorBase {
+dictionary GPUPipelineDescriptorBase : GPUObjectDescriptorBase {
     required GPUPipelineLayout layout;
 };
 </script>
@@ -544,7 +552,7 @@ dictionary GPUComputePipelineDescriptor : GPUPipelineDescriptorBase {
     required GPUPipelineStageDescriptor computeStage;
 };
 
-interface GPUComputePipeline {
+interface GPUComputePipeline : GPUObjectBase {
 };
 </script>
 
@@ -575,7 +583,7 @@ dictionary GPURenderPipelineDescriptor : GPUPipelineDescriptorBase {
     // TODO other properties
 };
 
-interface GPURenderPipeline {
+interface GPURenderPipeline : GPUObjectBase {
 };
 </script>
 
@@ -583,11 +591,16 @@ Command Recording {#command-recording}
 ======================================
 
 <script type=idl>
-interface GPUProgrammablePassEncoder {
+interface GPUProgrammablePassEncoder : GPUObjectBase {
     void endPass();
 
     // Allowed in both compute and render passes
     void setBindGroup(u32 index, GPUBindGroup bindGroup, optional sequence<u64> dynamicOffsets);
+
+    // Debugging assistance
+    void pushDebugGroup(DOMString groupLabel);
+    void popDebugGroup();
+    void insertDebugMarker(DOMString markerLabel);
 };
 
 interface GPURenderPassEncoder : GPUProgrammablePassEncoder {
@@ -649,11 +662,17 @@ dictionary GPURenderPassDepthStencilAttachmentDescriptor {
     u32 clearStencil = 0;
 };
 
-dictionary GPURenderPassDescriptor {
+dictionary GPURenderPassDescriptor : GPUObjectDescriptorBase {
     required sequence<GPURenderPassColorAttachmentDescriptor> colorAttachments;
     GPURenderPassDepthStencilAttachmentDescriptor? depthStencilAttachment = null;
 };
 
+dictionary GPUComputePassDescriptor : GPUObjectDescriptorBase {
+};
+
+dictionary GPUCommandBufferDescriptor : GPUObjectDescriptorBase {
+};
+
 dictionary GPUBufferCopyView {
     required GPUBuffer buffer;
     u64 offset = 0;
@@ -668,12 +687,12 @@ dictionary GPUTextureCopyView {
     GPUOrigin3D origin = {x: 0, y: 0, z: 0};
 };
 
-interface GPUCommandBuffer {
+interface GPUCommandBuffer : GPUObjectBase {
 };
 
-interface GPUCommandEncoder {
+interface GPUCommandEncoder : GPUObjectBase {
     GPURenderPassEncoder beginRenderPass(GPURenderPassDescriptor descriptor);
-    GPUComputePassEncoder beginComputePass();
+    GPUComputePassEncoder beginComputePass(GPUComputePassEncoder? descriptor);
 
     // Commands allowed outside of "passes"
     void copyBufferToBuffer(
@@ -698,10 +717,10 @@ interface GPUCommandEncoder {
         GPUTextureCopyView destination,
         GPUExtent3D copySize);
 
-    GPUCommandBuffer finish();
+    GPUCommandBuffer finish(GPUCommandBufferDescriptor? descriptor);
 };
 
-dictionary GPUCommandEncoderDescriptor {
+dictionary GPUCommandEncoderDescriptor : GPUObjectDescriptorBase {
     //TODO: reusability flag?
 };
 </script>
@@ -710,11 +729,11 @@ Fences {#fences}
 ================
 
 <script type=idl>
-dictionary GPUFenceDescriptor {
+dictionary GPUFenceDescriptor : GPUObjectDescriptorBase {
     u64 initialValue = 0;
 };
 
-interface GPUFence {
+interface GPUFence : GPUObjectBase {
     u64 getCompletedValue();
     Promise<void> onCompletion(u64 completionValue);
 };
@@ -724,7 +743,7 @@ Queues {#queues}
 ================
 
 <script type=idl>
-interface GPUQueue {
+interface GPUQueue : GPUObjectBase {
     void submit(sequence<GPUCommandBuffer> buffers);
 
     GPUFence createFence(GPUFenceDescriptor descriptor);
@@ -744,13 +763,13 @@ interface GPUCanvasContext {
     Promise<GPUTextureFormat> getSwapChainPreferredFormat(GPUDevice device);
 }
 
-dictionary GPUSwapChainDescriptor {
+dictionary GPUSwapChainDescriptor : GPUObjectDescriptorBase {
     required GPUDevice device;
     required GPUTextureFormat format;
     GPUTextureUsageFlags usage = GPUTextureUsage.OUTPUT_ATTACHMENT;
 };
 
-interface GPUSwapChain {
+interface GPUSwapChain : GPUObjectBase {
     GPUTexture getCurrentTexture();
 };
 </script>
@@ -768,7 +787,7 @@ dictionary GPULimits {
 };
 
 // Device
-interface GPUDevice {
+interface GPUDevice : GPUObjectBase {
     readonly attribute GPUExtensions extensions;
     readonly attribute GPULimits limits;
     readonly attribute GPUAdapter adapter;
@@ -792,14 +811,14 @@ interface GPUDevice {
     GPUQueue getQueue();
 };
 
-dictionary GPUDeviceDescriptor {
+dictionary GPUDeviceDescriptor : GPUObjectDescriptorBase {
     GPUExtensions extensions;
     GPULimits limits;
 
     // TODO are other things configurable like queues?
 };
 
-interface GPUAdapter {
+interface GPUAdapter : GPUObjectBase {
     readonly attribute DOMString name;
     readonly attribute GPUExtensions extensions;
     //readonly attribute GPULimits limits; Don't expose higher limits for now.
@@ -899,50 +918,3 @@ partial interface GPUDevice : EventTarget {
     attribute EventHandler onuncapturederror;
 };
 </script>
-
-Debugging Assistance {#debugging}
-=================================
-
-<script type=idl>
-partial interface GPUProgrammablePassEncoder {
-    void pushDebugGroup(DOMString groupLabel);
-    void popDebugGroup();
-    void insertDebugMarker(DOMString markerLabel);
-};
-
-interface mixin GPUDebugLabel {
-    attribute DOMString label;
-};
-
-GPUBindGroup includes GPUDebugLabel;
-GPUBindGroupLayout includes GPUDebugLabel;
-GPUBuffer includes GPUDebugLabel;
-GPUCommandBuffer includes GPUDebugLabel;
-GPUCommandEncoder includes GPUDebugLabel;
-GPUComputePipeline includes GPUDebugLabel;
-GPUFence includes GPUDebugLabel;
-GPUPipelineLayout includes GPUDebugLabel;
-GPUProgrammablePassEncoder includes GPUDebugLabel;
-GPUQueue includes GPUDebugLabel;
-GPURenderPipeline includes GPUDebugLabel;
-GPUSampler includes GPUDebugLabel;
-GPUShaderModule includes GPUDebugLabel;
-GPUTexture includes GPUDebugLabel;
-GPUTextureView includes GPUDebugLabel;
-
-partial dictionary GPUCommandEncoderDescriptor {
-    DOMString label;
-};
-
-partial dictionary GPUFenceDescriptor {
-    DOMString label;
-};
-
-partial dictionary GPUPipelineDescriptorBase {
-    DOMString label;
-};
-
-partial dictionary GPUShaderModuleDescriptor {
-    DOMString label;
-};
-</script>