Improve loading attribute for HTMLImageElement (#1220)

Co-authored-by: saschanaz <[email protected]>

Author: Shogo Sensui

baselines/dom.generated.d.ts

@@ -6672,7 +6672,8 @@ interface HTMLImageElement extends HTMLElement {
     hspace: number;
     /** Sets or retrieves whether the image is a server-side image map. */
     isMap: boolean;
-    loading: string;
+    /** Sets or retrieves the policy for loading image elements that are outside the viewport. */
+    loading: "eager" | "lazy";
     /**
      * Sets or retrieves a Uniform Resource Identifier (URI) to a long description of the object.
      * @deprecated

inputfiles/addedTypes.jsonc

@@ -309,7 +309,7 @@
                     "hue",
                     "saturation",
                     "color",
-                    "luminosity"          
+                    "luminosity"
                 ]
             }
         }
@@ -354,6 +354,9 @@
                         "decoding": {
                             "name": "decoding",
                             "overrideType": "\"async\" | \"sync\" | \"auto\""
+                        },
+                        "loading": {
+                            "overrideType": "\"eager\" | \"lazy\""
                         }
                     }
                 }

inputfiles/comments.json

@@ -553,6 +553,9 @@
                         "hspace": {
                             "comment": "Sets or retrieves the width of the border to draw around the object."
                         },
+                        "loading": {
+                            "comment": "Sets or retrieves the policy for loading image elements that are outside the viewport."
+                        },
                         "longDesc": {
                             "comment": "Sets or retrieves a Uniform Resource Identifier (URI) to a long description of the object."
                         },