Make Device::CreateSamplerImpl to return a ResultOrError

This will allow backends to do error-handling internally for things like
allocation failures though non of them take advantage of it yet.

src/backend/Device.cpp

@@ -139,7 +139,13 @@ namespace backend {
             return nullptr;
         }
 
-        return CreateSamplerImpl(descriptor);
+        ResultOrError<SamplerBase*> maybeSampler = CreateSamplerImpl(descriptor);
+        if (maybeSampler.IsError()) {
+            // TODO(cwallez@chromium.org): Implement the WebGPU error handling mechanism.
+            delete validation.AcquireError();
+            return nullptr;
+        }
+        return maybeSampler.AcquireSuccess();
     }
     ShaderModuleBuilder* DeviceBase::CreateShaderModuleBuilder() {
         return new ShaderModuleBuilder(this);

src/backend/Device.h

@@ -15,6 +15,7 @@
 #ifndef BACKEND_DEVICEBASE_H_
 #define BACKEND_DEVICEBASE_H_
 
+#include "backend/Error.h"
 #include "backend/Forward.h"
 #include "backend/RefCounted.h"
 
@@ -98,7 +99,8 @@ namespace backend {
         void Release();
 
       private:
-        virtual SamplerBase* CreateSamplerImpl(const nxt::SamplerDescriptor* descriptor) = 0;
+        virtual ResultOrError<SamplerBase*> CreateSamplerImpl(
+            const nxt::SamplerDescriptor* descriptor) = 0;
 
         // The object caches aren't exposed in the header as they would require a lot of
         // additional includes.

src/backend/d3d12/D3D12Backend.cpp

@@ -298,7 +298,8 @@ namespace backend { namespace d3d12 {
     RenderPipelineBase* Device::CreateRenderPipeline(RenderPipelineBuilder* builder) {
         return new RenderPipeline(builder);
     }
-    SamplerBase* Device::CreateSamplerImpl(const nxt::SamplerDescriptor* descriptor) {
+    ResultOrError<SamplerBase*> Device::CreateSamplerImpl(
+        const nxt::SamplerDescriptor* descriptor) {
         return new Sampler(this, descriptor);
     }
     ShaderModuleBase* Device::CreateShaderModule(ShaderModuleBuilder* builder) {

src/backend/d3d12/D3D12Backend.h

@@ -128,7 +128,8 @@ namespace backend { namespace d3d12 {
         void ExecuteCommandLists(std::initializer_list<ID3D12CommandList*> commandLists);
 
       private:
-        SamplerBase* CreateSamplerImpl(const nxt::SamplerDescriptor* descriptor) override;
+        ResultOrError<SamplerBase*> CreateSamplerImpl(
+            const nxt::SamplerDescriptor* descriptor) override;
 
         uint64_t mSerial = 0;
         ComPtr<ID3D12Fence> mFence;

src/backend/metal/MetalBackend.h

@@ -118,7 +118,8 @@ namespace backend { namespace metal {
         ResourceUploader* GetResourceUploader() const;
 
       private:
-        SamplerBase* CreateSamplerImpl(const nxt::SamplerDescriptor* descriptor) override;
+        ResultOrError<SamplerBase*> CreateSamplerImpl(
+            const nxt::SamplerDescriptor* descriptor) override;
 
         void OnCompletedHandler();
 

src/backend/metal/MetalBackend.mm

@@ -117,7 +117,8 @@ namespace backend { namespace metal {
     RenderPipelineBase* Device::CreateRenderPipeline(RenderPipelineBuilder* builder) {
         return new RenderPipeline(builder);
     }
-    SamplerBase* Device::CreateSamplerImpl(const nxt::SamplerDescriptor* descriptor) {
+    ResultOrError<SamplerBase*> Device::CreateSamplerImpl(
+        const nxt::SamplerDescriptor* descriptor) {
         return new Sampler(this, descriptor);
     }
     ShaderModuleBase* Device::CreateShaderModule(ShaderModuleBuilder* builder) {

src/backend/null/NullBackend.cpp

@@ -76,7 +76,8 @@ namespace backend { namespace null {
     RenderPipelineBase* Device::CreateRenderPipeline(RenderPipelineBuilder* builder) {
         return new RenderPipeline(builder);
     }
-    SamplerBase* Device::CreateSamplerImpl(const nxt::SamplerDescriptor* descriptor) {
+    ResultOrError<SamplerBase*> Device::CreateSamplerImpl(
+        const nxt::SamplerDescriptor* descriptor) {
         return new Sampler(this, descriptor);
     }
     ShaderModuleBase* Device::CreateShaderModule(ShaderModuleBuilder* builder) {

src/backend/null/NullBackend.h

@@ -120,7 +120,8 @@ namespace backend { namespace null {
         std::vector<std::unique_ptr<PendingOperation>> AcquirePendingOperations();
 
       private:
-        SamplerBase* CreateSamplerImpl(const nxt::SamplerDescriptor* descriptor) override;
+        ResultOrError<SamplerBase*> CreateSamplerImpl(
+            const nxt::SamplerDescriptor* descriptor) override;
 
         std::vector<std::unique_ptr<PendingOperation>> mPendingOperations;
     };

src/backend/opengl/OpenGLBackend.cpp

@@ -86,7 +86,8 @@ namespace backend { namespace opengl {
     RenderPipelineBase* Device::CreateRenderPipeline(RenderPipelineBuilder* builder) {
         return new RenderPipeline(builder);
     }
-    SamplerBase* Device::CreateSamplerImpl(const nxt::SamplerDescriptor* descriptor) {
+    ResultOrError<SamplerBase*> Device::CreateSamplerImpl(
+        const nxt::SamplerDescriptor* descriptor) {
         return new Sampler(this, descriptor);
     }
     ShaderModuleBase* Device::CreateShaderModule(ShaderModuleBuilder* builder) {

src/backend/opengl/OpenGLBackend.h

@@ -105,7 +105,8 @@ namespace backend { namespace opengl {
         void TickImpl() override;
 
       private:
-        SamplerBase* CreateSamplerImpl(const nxt::SamplerDescriptor* descriptor) override;
+        ResultOrError<SamplerBase*> CreateSamplerImpl(
+            const nxt::SamplerDescriptor* descriptor) override;
     };
 
     class BindGroup : public BindGroupBase {

src/backend/vulkan/VulkanBackend.cpp

@@ -253,7 +253,8 @@ namespace backend { namespace vulkan {
     RenderPipelineBase* Device::CreateRenderPipeline(RenderPipelineBuilder* builder) {
         return new RenderPipeline(builder);
     }
-    SamplerBase* Device::CreateSamplerImpl(const nxt::SamplerDescriptor* descriptor) {
+    ResultOrError<SamplerBase*> Device::CreateSamplerImpl(
+        const nxt::SamplerDescriptor* descriptor) {
         return new Sampler(this, descriptor);
     }
     ShaderModuleBase* Device::CreateShaderModule(ShaderModuleBuilder* builder) {

src/backend/vulkan/VulkanBackend.h

@@ -133,7 +133,8 @@ namespace backend { namespace vulkan {
         void TickImpl() override;
 
       private:
-        SamplerBase* CreateSamplerImpl(const nxt::SamplerDescriptor* descriptor) override;
+        ResultOrError<SamplerBase*> CreateSamplerImpl(
+            const nxt::SamplerDescriptor* descriptor) override;
 
         bool CreateInstance(VulkanGlobalKnobs* usedKnobs,
                             const std::vector<const char*>& requiredExtensions);