Merge pull request #1209 from WebPlatformForEmbedded/pgorszkowski/2.38/Implement-list-of-available-images-matching-logic

Implement list of available images matching logic

Author: magomez

LayoutTests/imported/w3c/web-platform-tests/html/semantics/embedded-content/the-img-element/image-loading-lazy-available-expected.txt

@@ -1,5 +1,5 @@
 
 
 
-FAIL The list of available images gets checked before deciding to make a load lazy assert_equals: The list of available images should be checked before delaying the image load expected 256 but got 0
+PASS The list of available images gets checked before deciding to make a load lazy
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/embedded-content/the-img-element/image-loading-lazy-use-list-of-available-images-expected.txt

@@ -1,4 +1,4 @@
 
 
-FAIL Lazyload images can load immediately from the list of available images promise_test: Unhandled rejection with value: object "Error: The `loading=lazy` image should load immediately from the list of available images, beating this timeout promise."
+PASS Lazyload images can load immediately from the list of available images
 

Source/WebCore/loader/ImageLoader.cpp

@@ -42,6 +42,7 @@
 #include "InspectorInstrumentation.h"
 #include "JSDOMPromiseDeferred.h"
 #include "LazyLoadImageObserver.h"
+#include "MemoryCache.h"
 #include "Page.h"
 #include "RenderImage.h"
 #include "RenderSVGImage.h"
@@ -97,6 +98,22 @@ static inline bool pageIsBeingDismissed(Document& document)
     return frame && frame->loader().pageDismissalEventBeingDispatched() != FrameLoader::PageDismissalType::None;
 }
 
+// https://html.spec.whatwg.org/multipage/images.html#updating-the-image-data:list-of-available-images
+static bool canReuseFromListOfAvailableImages(const CachedResourceRequest& request, Document& document)
+{
+    CachedResource* resource = MemoryCache::singleton().resourceForRequest(request.resourceRequest(), document.page()->sessionID());
+    if (!resource || resource->stillNeedsLoad() || resource->isPreloaded())
+        return false;
+
+    if (resource->options().mode == FetchOptions::Mode::Cors && !document.securityOrigin().isSameOriginAs(*resource->origin()))
+        return false;
+
+    if (resource->options().mode != request.options().mode || resource->options().credentials != request.options().credentials)
+        return false;
+
+    return true;
+}
+
 ImageLoader::ImageLoader(Element& element)
     : m_element(element)
     , m_image(nullptr)
@@ -214,7 +231,7 @@ void ImageLoader::updateFromElement(RelevantMutation relevantMutation)
         } else {
             if (m_lazyImageLoadState == LazyImageLoadState::None && isImageElement) {
                 auto& imageElement = downcast<HTMLImageElement>(element());
-                if (imageElement.isLazyLoadable() && document.lazyImageLoadingEnabled()) {
+                if (imageElement.isLazyLoadable() && document.lazyImageLoadingEnabled() && !canReuseFromListOfAvailableImages(request, document)) {
                     m_lazyImageLoadState = LazyImageLoadState::Deferred;
                     request.setIgnoreForRequestCount(true);
                 }