fix media query issue

Runtime/editor/editor_utils.cs

             this._lastDevicePixelRatio = GameViewUtil.getGameViewDevicePixelRatio();
         }
 
+        public void OnEnable() {
+            this._lastDevicePixelRatio = GameViewUtil.getGameViewDevicePixelRatio();
+        }
+        
         public float DevicePixelRatio {
             get { return this._lastDevicePixelRatio; }
         }

Runtime/engine/DisplayMetrics.cs

     }
 
     public interface DisplayMetrics {
+        void OnEnable();
-
         void Update();
 
         float DevicePixelRatio { get; } 
         
         float _devicePixelRatio = 0;
+
+        public void OnEnable() {
+        }
 
         public void OnGUI() {
             

Runtime/engine/UIWidgetsPanel.cs

             Input.simulateMouseWithTouches = false;
 
             this._displayMetrics = DisplayMetricsProvider.provider();
-
+            this._displayMetrics.OnEnable();
+            
             if (_repaintEvent == null) {
                 _repaintEvent = new Event {type = EventType.Repaint};
             }

Samples/UIWidgetSample/TextInputSample.cs

             return new _EditableInputTypeWidgetState();
         }
     }
-
+    
-        bool unityKeyboard = false;
-                //width:300,
-                        // widget,
                     }
                 ));
         }