Notify LayoutImage that intrinsic dimensions changed when sizes changes

When the sizes attribute changes, that has the potential of modifying the image's intrinsic dimensions. However, the LayoutImage object was not notified of that explicitly. While the intrinsic dimensions were changed when a new resource was downloaded as a result of the sizes attribute change, that wasn't the case when such the resource was not changed. This CL fixes that, by explicitly notifying the LayoutImage of the change. BUG=639845 Review-Url: https://codereview.chromium.org/2292013002 Cr-Commit-Position: refs/heads/master@{#415369}

Notify LayoutImage that intrinsic dimensions changed when sizes changes
When the sizes attribute changes, that has the potential of modifying the image's intrinsic dimensions. However, the LayoutImage object was not notified of that explicitly. While the intrinsic dimensions were changed when a new resource was downloaded as a result of the sizes attribute change, that wasn't the case when such the resource was not changed. This CL fixes that, by explicitly notifying the LayoutImage of the change. BUG=639845 Review-Url: https://codereview.chromium.org/2292013002 Cr-Commit-Position: refs/heads/master@{#415369}
caccabc0 · yoav · Commit bot · be8b5afc · caccabc0 · caccabc0
Commit caccabc0 authored Aug 30, 2016 by yoav Committed by Commit bot Aug 30, 2016
2 changed files
--- a/third_party/WebKit/LayoutTests/fast/dom/HTMLImageElement/sizes-changed-intrinsic-size-update.html
+++ b/third_party/WebKit/LayoutTests/fast/dom/HTMLImageElement/sizes-changed-intrinsic-size-update.html
+<!DOCTYPE html>
+<script src="../../../resources/testharness.js"></script>
+<script src="../../../resources/testharnessreport.js"></script>
+<body>
+<img id="image"
+	srcset="resources/black.png 100w,
+			resources/image-set-4x.png 1600w"
+	sizes="100px"
+>
+<script>
+    var t = async_test('Make sure that a sizes change also changes the intrinsic dimensions');
+    window.onload = t.step_func(function() {
+
+        var img = document.getElementById("image");
+        img.onload = t.step_func(function() {
+            assert_equals(img.width, 1600);
+            img.onload = function(){};
+            img.sizes = "100px";
+            assert_equals(img.width, 100);
+            t.done();
+        });
+        img.sizes = "1600px";
+    });
+</script>
+</body>
+</html>
--- a/third_party/WebKit/Source/core/html/HTMLImageElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLImageElement.cpp
@@ -227,6 +227,7 @@ void HTMLImageElement::setBestFitURLAndDPRFromImageCandidate(const ImageCandidat
 {
    m_bestFitImageURL = candidate.url();
    float candidateDensity = candidate.density();
+    float oldImageDevicePixelRatio = m_imageDevicePixelRatio;
    if (candidateDensity >= 0)
        m_imageDevicePixelRatio = 1.0 / candidateDensity;

@@ -237,9 +238,13 @@ void HTMLImageElement::setBestFitURLAndDPRFromImageCandidate(const ImageCandidat
    } else if (!candidate.srcOrigin()) {
        UseCounter::count(document(), UseCounter::SrcsetXDescriptor);
    }
-    if (layoutObject() && layoutObject()->isImage())
+    if (layoutObject() && layoutObject()->isImage()) {
        LayoutImageItem(toLayoutImage(layoutObject())).setImageDevicePixelRatio(m_imageDevicePixelRatio);

+        if (oldImageDevicePixelRatio != m_imageDevicePixelRatio)
+            toLayoutImage(layoutObject())->intrinsicSizeChanged();
+    }
+
    if (intrinsicSizingViewportDependant) {
        if (!m_listener)
            m_listener = ViewportChangeListener::create(this);