Merge pull request #1040 from Unity-Technologies/debug-window-tweak

Disallowed using the editor debug window at the same time as the runtime one

ScriptableRenderPipeline/Core/CoreRP/Editor/Debugging/DebugWindow.cs

         static Dictionary<Type, Type> s_WidgetStateMap; // DebugUI.Widget type -> DebugState type
         static Dictionary<Type, DebugUIDrawer> s_WidgetDrawerMap; // DebugUI.Widget type -> DebugUIDrawer
 
+        bool m_IsActiveInPlayMode
+        {
+            get { return Application.isPlaying && DebugManager.instance.displayRuntimeUI; }
+        }
+
         [DidReloadScripts]
         static void OnEditorReload()
         {
 
         void Update()
         {
+            if (m_IsActiveInPlayMode)
+                return;
+
             int treeState = DebugManager.instance.GetState();
 
             if (m_DebugTreeState != treeState || m_IsDirty)
         {
             if (s_Styles == null)
                 s_Styles = new Styles();
+
+            if (m_IsActiveInPlayMode)
+            {
+                EditorGUILayout.HelpBox("The editor debug window is disabled while the runtime one is active.", MessageType.Info);
+                return;
+            }
 
             var panels = DebugManager.instance.panels;
             int itemCount = panels.Count(x => !x.isRuntimeOnly && x.children.Count(w => !w.isRuntimeOnly) > 0);