Merge remote-tracking branch 'upstream/master' into dpi

README.md

 3. **Refine Code Style Rules**: Edit the ".editorconfig" file under \<YourProjectPath\>/Packages/com.unity.uiwidgets/". Visit
  https://www.jetbrains.com/help/rider/EditorConfig_Index.html for the detailed.
 
+#### Generate njk Code
+
+1. **Go to scripts Folder and Run npm install**:
+```
+cd <YourProjectPath>/Packages/com.unity.uiwidgets/scripts
+npm install
+```
+
+2. **Run the codegen Command**:
+```
+node uiwidgets-cli.js codegen . generate mixin code
+```

Runtime/async/coroutine.cs

                     callbackNode.callback();
                 }
                 catch (Exception ex) {
-                    Debug.LogError("Failed to execute callback in BackgroundCallbacks: " + ex);
+                    D.logError("Failed to execute callback in BackgroundCallbacks: ", ex);
                 }
 
                 if (!callbackNode.isDone) {

Runtime/async/microtask_queue.cs

                     action();
                 }
                 catch (Exception ex) {
-                    Debug.LogError("Error to execute microtask: " + ex);
+                    D.logError("Error to execute microtask: ", ex);
                 }
             }
         }

Runtime/async/timer.cs

                     callback();
                 }
                 catch (Exception ex) {
-                    Debug.LogError("Error to execute runInMain callback: " + ex);
+                    D.logError("Error to execute runInMain callback: ", ex);
                 }
             }
         }
                     this._callback();
                 }
                 catch (Exception ex) {
-                    Debug.LogError("Error to execute timer callback: " + ex);
+                    D.logError("Error to execute timer callback: ", ex);
                 }
 
                 if (this.periodic) {

Runtime/engine/DisplayMetrics.cs

 using System;
-#if UNITY_ANDROID 
+using System.Runtime.InteropServices;
-#endif
+
 namespace Unity.UIWidgets.engine {
 
     public static class DisplayMetricsProvider {

Runtime/foundation/assertions.cs

         }
     }
 
-    public class UIWidgetsError : AssertionError {
+    public class UIWidgetsError : Exception {
-
-        static int _errorCount = 0;
-
-        public static void resetErrorCount() {
-            _errorCount = 0;
-        }
 
         public static void dumpErrorToConsole(UIWidgetsErrorDetails details) {
             dumpErrorToConsole(details, forceReport: false);
                 return;
             }
 
-            if (_errorCount == 0 || forceReport) {
-                Debug.LogError(details.ToString());
-            }
-            else {
-                Debug.LogWarning("Another exception was thrown: " + details);
-            }
-
-            _errorCount += 1;
+            D.logError(details.ToString(), details.exception);
         }
 
         public static IEnumerable<string> defaultStackFilter(IEnumerable<string> frames) {

Runtime/foundation/debug.cs

 using System.Diagnostics;
 using System.Linq;
 using Unity.UIWidgets.ui;
+using Debug = UnityEngine.Debug;
+
+        public static void logError(string message, Exception ex = null) {
+            Debug.LogException(new ReportError(message, ex));
+        }
-            assert(result(), message);
+            if (!result()) {
+                throw new AssertionError(message);
+            }
         }
 
         [Conditional("UIWidgets_DEBUG")]
 
         public override string StackTrace {
             get {
+                var stackTrace = base.StackTrace;
+                var lines = stackTrace.Split('\n');
+                var strippedLines = lines.Skip(1);
+
+                return string.Join("\n", strippedLines);
+            }
+        }
+    }
+    
+    
+    public class ReportError : Exception {
+        Exception ex;
+        public ReportError(string message, Exception ex = null) : base(message) {
+            this.ex = ex;
+        }
+
+        public override string StackTrace {
+            get {
+                if (this.ex != null) {
+                    return this.ex.StackTrace;
+                }
+                
                 var stackTrace = base.StackTrace;
                 var lines = stackTrace.Split('\n');
                 var strippedLines = lines.Skip(1);

Runtime/gestures/binding.cs

                     entry.target.handleEvent(evt, entry);
                 }
                 catch (Exception ex) {
-                    Debug.LogError("Error while dispatching a pointer event: " + ex);
+                    D.logError("Error while dispatching a pointer event: ", ex);
                 }
             }
         }

Runtime/gestures/pointer_router.cs

                 route(evt);
             }
             catch (Exception ex) {
-                Debug.LogError("Error while routing a pointer event: " + ex);
+                D.logError("Error while routing a pointer event: ", ex);
             }
         }
 

Runtime/rendering/box.mixin.gen.cs

-using System;
 using System.Collections.Generic;
 using Unity.UIWidgets.gestures;
 using Unity.UIWidgets.ui;

Runtime/rendering/proxy_box.mixin.njk

                 return this.child.getMinIntrinsicWidth(height);
             }
 
-            return 0.0;
+            return 0.0f;
         }
 
         protected override float computeMaxIntrinsicWidth(float height) {
 
-            return 0.0;
+            return 0.0f;
         }
 
         protected override float computeMinIntrinsicHeight(float width) {
 
-            return 0.0;
+            return 0.0f;
         }
 
         protected override float computeMaxIntrinsicHeight(float width) {
 
-            return 0.0;
+            return 0.0f;
         }
 
         protected override float? computeDistanceToActualBaseline(TextBaseline baseline) {