Adds pass labels into the commands and plumbs through for Metal.

Bug: dawn:1784
Change-Id: Ie71360d83c4f3c47821916ebf8a187662e3f286f
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/131100
Commit-Queue: Loko Kung <lokokung@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Austin Eng <enga@chromium.org>

src/dawn/native/CommandEncoder.cpp

@@ -764,6 +764,7 @@ Ref<ComputePassEncoder> CommandEncoder::BeginComputePass(const ComputePassDescri
             if (descriptor == nullptr) {
                 return {};
             }
+            cmd->label = std::string(descriptor->label ? descriptor->label : "");
 
             // Record timestamp writes at the beginning and end of compute pass. The timestamp write
             // at the end also be needed in BeginComputePassCmd because it's required by compute
@@ -839,6 +840,7 @@ Ref<RenderPassEncoder> CommandEncoder::BeginRenderPass(const RenderPassDescripto
             mEncodingContext.WillBeginRenderPass();
             BeginRenderPassCmd* cmd =
                 allocator->Allocate<BeginRenderPassCmd>(Command::BeginRenderPass);
+            cmd->label = std::string(descriptor->label ? descriptor->label : "");
 
             cmd->attachmentState = device->GetOrCreateAttachmentState(descriptor);
             attachmentState = cmd->attachmentState;

src/dawn/native/Commands.h

@@ -17,6 +17,7 @@
 
 #include <array>
 #include <bitset>
+#include <string>
 #include <vector>
 
 #include "dawn/common/Constants.h"
@@ -83,6 +84,7 @@ struct BeginComputePassCmd {
 
     TimestampWrite beginTimestamp;
     TimestampWrite endTimestamp;
+    std::string label;
 };
 
 struct BeginOcclusionQueryCmd {
@@ -135,6 +137,7 @@ struct BeginRenderPassCmd {
     Ref<QuerySetBase> occlusionQuerySet;
     TimestampWrite beginTimestamp;
     TimestampWrite endTimestamp;
+    std::string label;
 };
 
 struct BufferCopy {

src/dawn/native/metal/CommandBufferMTL.mm

@@ -1227,6 +1227,7 @@ MaybeError CommandBuffer::EncodeComputePass(CommandRecordingContext* commandCont
             }
         }
     }
+    SetDebugName(GetDevice(), encoder, "Dawn_ComputePassEncoder", computePassCmd->label);
 
     Command type;
     while (mCommands.NextCommandId(&type)) {
@@ -1388,6 +1389,7 @@ MaybeError CommandBuffer::EncodeRenderPass(id<MTLRenderCommandEncoder> encoder,
                                 withBarrier:YES];
         }
     }
+    SetDebugName(GetDevice(), encoder, "Dawn_RenderPassEncoder", renderPassCmd->label);
 
     auto EncodeRenderBundleCommand = [&](CommandIterator* iter, Command type) {
         switch (type) {