fix(common): forward sizes and srcset to preload link tag

Set imagesrcset and imagesizes on preload `<link>` tag

packages/common/src/directives/ng_optimized_image/ng_optimized_image.ts

@@ -291,6 +291,13 @@ export class NgOptimizedImage implements OnInit, OnChanges, OnDestroy {
    */
   @Input() srcset?: string;
 
+  /**
+   * Value of the `sizes` attribute if set on the host `<img>` element.
+   * This input is exclusively read to pass along to the preload `<link>` attribute for this image.
+   * @internal
+   */
+  @Input() sizes?: string;
+
   ngOnInit() {
     if (ngDevMode) {
       assertNonEmptyInput(this, 'ngSrc', this.ngSrc);
@@ -330,15 +337,16 @@ export class NgOptimizedImage implements OnInit, OnChanges, OnDestroy {
     this.setHostAttribute('fetchpriority', this.getFetchPriority());
     // The `src` and `srcset` attributes should be set last since other attributes
     // could affect the image's loading behavior.
-    const rewrittenSrc = this.getRewrittenSrc();
-    this.setHostAttribute('src', rewrittenSrc);
+    this.setHostAttribute('src', this.getRewrittenSrc());
+
+    const rewrittenSrcset = this.getRewrittenSrcset();
 
     if (this.ngSrcset) {
-      this.setHostAttribute('srcset', this.getRewrittenSrcset());
+      this.setHostAttribute('srcset', rewrittenSrcset);
     }
 
     if (this.isServer && this.priority) {
-      this.createPreloadLinkTag(rewrittenSrc);
+      this.createPreloadLinkTag(this.ngSrc, rewrittenSrcset, this.sizes);
     }
   }
 
@@ -394,7 +402,7 @@ export class NgOptimizedImage implements OnInit, OnChanges, OnDestroy {
     this.renderer.setAttribute(this.imgElement, name, value);
   }
 
-  private createPreloadLinkTag(url: string): void {
+  private createPreloadLinkTag(url: string, srcset: string, sizes?: string): void {
     if (ngDevMode) {
       if (this.preloadedImages.size >= DEFAULT_PRELOADED_IMAGES_LIMIT) {
         throw new RuntimeError(
@@ -415,6 +423,10 @@ export class NgOptimizedImage implements OnInit, OnChanges, OnDestroy {
     preload.setAttribute('as', 'image');
     preload.href = url;
     preload.rel = 'preload';
+    if (sizes) {
+      preload.imageSizes = sizes;
+    }
+    preload.imageSrcset = srcset;
 
     this.document.head.appendChild(preload);
   }