Add a D3D12MarkerRegion for future use

* Not used yet, as I need to figure out how to apply list markers when
  we record multiple individual lists. Doing open/close of a list just
  for the marker seems wasteful. It could be fired directly at the queue

renderdoc/driver/d3d12/d3d12_common.cpp

@@ -28,6 +28,32 @@
 #include "d3d12_manager.h"
 #include "d3d12_resources.h"
 
+D3D12MarkerRegion::D3D12MarkerRegion(ID3D12GraphicsCommandList *l, const std::string &marker)
+{
+  list = l;
+
+  if(list)
+  {
+    std::wstring text = StringFormat::UTF82Wide(marker);
+    list->BeginEvent(0, text.c_str(), (UINT)text.size());
+  }
+}
+
+void D3D12MarkerRegion::Set(ID3D12GraphicsCommandList *list, const std::string &marker)
+{
+  if(list)
+  {
+    std::wstring text = StringFormat::UTF82Wide(marker);
+    list->SetMarker(0, text.c_str(), (UINT)text.size());
+  }
+}
+
+D3D12MarkerRegion::~D3D12MarkerRegion()
+{
+  if(list)
+    list->EndEvent();
+}
+
 static ShaderConstant MakeConstantBufferVariable(const DXBC::CBufferVariable &var, uint32_t &offset);
 
 static ShaderVariableType MakeShaderVariableType(DXBC::CBufferVariableType type, uint32_t &offset)

renderdoc/driver/d3d12/d3d12_common.h

@@ -33,6 +33,16 @@
 #include "driver/shaders/dxbc/dxbc_compile.h"
 #include "serialise/serialiser.h"
 
+// replay only class for handling marker regions
+struct D3D12MarkerRegion
+{
+  D3D12MarkerRegion(ID3D12GraphicsCommandList *list, const std::string &marker);
+  ~D3D12MarkerRegion();
+  static void Set(ID3D12GraphicsCommandList *list, const std::string &marker);
+
+  ID3D12GraphicsCommandList *list;
+};
+
 void MakeShaderReflection(DXBC::DXBCFile *dxbc, ShaderReflection *refl,
                           ShaderBindpointMapping *mapping);