Start adding LW tests.

TestProjects/LWGraphicsTest/Packages/manifest.json

     "com.unity.analytics": "2.0.16",
     "com.unity.collab-proxy": "1.2.4-preview",
     "com.unity.package-manager-ui": "2.0.0-preview.2",
+    "com.unity.testframework.graphics": "file:../../../com.unity.testframework.graphics",
     "com.unity.postprocessing": "file:../../../com.unity.postprocessing",
     "com.unity.purchasing": "2.0.1",
     "com.unity.render-pipelines.core": "file:../../../com.unity.render-pipelines.core",
     "com.unity.modules.vr": "1.0.0",
     "com.unity.modules.wind": "1.0.0",
     "com.unity.modules.xr": "1.0.0"
-  }
+  },
+  "testables": [
+    "com.unity.render-pipelines.lightweight",
+    "com.unity.testframework.graphics"
+  ]
 }

TestProjects/LWGraphicsTest/Assets/CommonAssets/Scripts/LWGraphicsTestSettings.cs.meta

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TestProjects/LWGraphicsTest/Assets/CommonAssets/Scripts/LWGraphicsTestSettings.cs

+using UnityEngine.TestTools.Graphics;
+
+public class LWGraphicsTestSettings : GraphicsTestSettings
+{
+    public int WaitFrames = 0;
+}

TestProjects/LWGraphicsTest/Assets/CommonAssets/Scripts/LWGraphicsTests.asmdef

+{
+    "name": "LWGraphicsTests",
+    "references": [
+        "UnityEngine.TestTools.Graphics"
+    ],
+    "optionalUnityReferences": [
+        "TestAssemblies"
+    ],
+    "includePlatforms": [],
+    "excludePlatforms": [],
+    "allowUnsafeCode": false
+}

TestProjects/LWGraphicsTest/Assets/CommonAssets/Scripts/LWGraphicsTests.asmdef.meta

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TestProjects/LWGraphicsTest/Assets/CommonAssets/Scripts/LWGraphicsTests.cs

+using System.Collections;
+using NUnit.Framework;
+using UnityEngine;
+using UnityEngine.TestTools;
+using UnityEngine.TestTools.Graphics;
+using UnityEngine.SceneManagement;
+
+public class LWGraphicsTests
+{
+    [UnityTest, Category("LightWeightRP")]
+    [PrebuildSetup("SetupGraphicsTestCases")]
+    [UseGraphicsTestCases]
+    public IEnumerator Run(GraphicsTestCase testCase)
+    {
+        SceneManager.LoadScene(testCase.ScenePath);
+
+        // Always wait one frame for scene load
+        yield return null;
+
+        var camera = GameObject.FindGameObjectWithTag("MainCamera").GetComponent<Camera>();
+        var settings = Object.FindObjectOfType<LWGraphicsTestSettings>();
+        Assert.IsNotNull(settings, "Invalid test scene, couldn't find PostProcessingGraphicsTestSettings");
+
+        for (int i = 0; i < settings.WaitFrames; i++)
+            yield return null;
+
+        ImageAssert.AreEqual(testCase.ReferenceImage, camera, settings.ImageComparisonSettings);
+    }
+
+#if UNITY_EDITOR
+    [TearDown]
+    public void DumpImagesInEditor()
+    {
+        UnityEditor.TestTools.Graphics.ResultsUtility.ExtractImagesFromTestProperties(TestContext.CurrentContext.Test);
+    }
+#endif
+}

TestProjects/LWGraphicsTest/Assets/CommonAssets/Scripts/LWGraphicsTests.cs.meta

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TestProjects/LWGraphicsTest/Assets/CommonAssets/Scripts/Setup/LWEditorTests.asmdef

+{
+    "name": "LWEditorTests",
+    "references": [
+        "UnityEditor.TestTools.Graphics"
+    ],
+    "optionalUnityReferences": [
+        "TestAssemblies"
+    ],
+    "includePlatforms": [
+        "Editor"
+    ],
+    "excludePlatforms": [],
+    "allowUnsafeCode": false
+}

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TestProjects/LWGraphicsTest/Assets/CommonAssets/Scripts/Setup/SetupGraphicsTestCases.cs

+using UnityEngine.TestTools;
+
+// Work around case #1033694, unable to use PrebuildSetup types directly from assemblies that don't have special names.
+// Once that's fixed, this class can be deleted and the SetupGraphicsTestCases class in Unity.TestFramework.Graphics.Editor
+// can be used directly instead.
+public class SetupGraphicsTestCases : IPrebuildSetup
+{
+    public void Setup()
+    {
+        new UnityEditor.TestTools.Graphics.SetupGraphicsTestCases().Setup();
+    }
+}

TestProjects/LWGraphicsTest/Assets/CommonAssets/Scripts/Setup/SetupGraphicsTestCases.cs.meta

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TestProjects/LWGraphicsTest/Assets/CommonAssets/Scripts/Setup/SetupProject.cs

+using System;
+using System.Collections.Generic;
+using UnityEditor;
+using UnityEngine;
+using UnityEngine.Rendering;
+
+public static class SetupProject
+{
+    public static void ApplySettings()
+    {
+        var options = new Dictionary<string, Action>
+        {
+            { "gamma", () => PlayerSettings.colorSpace = ColorSpace.Gamma },
+            { "linear", () => PlayerSettings.colorSpace = ColorSpace.Linear },
+            { "glcore", () => SetGraphicsAPI(GraphicsDeviceType.OpenGLCore) },
+            { "d3d11", () => SetGraphicsAPI(GraphicsDeviceType.Direct3D11) },
+            { "d3d12", () => SetGraphicsAPI(GraphicsDeviceType.Direct3D12) },
+            { "vulkan", () => SetGraphicsAPI(GraphicsDeviceType.Vulkan) }
+        };
+
+        var args = Environment.GetCommandLineArgs();
+        foreach (var arg in args)
+        {
+            Action action;
+            if (options.TryGetValue(arg, out action))
+                action();
+        }
+    }
+
+    static void SetGraphicsAPI(GraphicsDeviceType api)
+    {
+        var currentTarget = EditorUserBuildSettings.activeBuildTarget;
+        PlayerSettings.SetGraphicsAPIs(currentTarget, new [] { api } );
+    }
+}

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