SVG Image intrinsic size should be used if css style size is 'auto'

third_party/WebKit/Source/core/layout/svg/LayoutSVGImage.cpp

Index: third_party/WebKit/Source/core/layout/svg/LayoutSVGImage.cpp
diff --git a/third_party/WebKit/Source/core/layout/svg/LayoutSVGImage.cpp b/third_party/WebKit/Source/core/layout/svg/LayoutSVGImage.cpp
index c49dccecaca90366e94c3ee6f092369eece6e2ff..eaff9b12a3679d0731192412c384b994528182c4 100644
--- a/third_party/WebKit/Source/core/layout/svg/LayoutSVGImage.cpp
+++ b/third_party/WebKit/Source/core/layout/svg/LayoutSVGImage.cpp
@@ -61,7 +61,36 @@ void LayoutSVGImage::willBeDestroyed()
     LayoutSVGModelObject::willBeDestroyed();
 }
 
-void LayoutSVGImage::updateBoundingBox()
+static float resolveWidthForRatio(float height, const FloatSize& intrinsicRatio)
+{
+    return height * intrinsicRatio.width() / intrinsicRatio.height();
+}
+
+static float resolveHeightForRatio(float width, const FloatSize& intrinsicRatio)
+{
+    return width * intrinsicRatio.height() / intrinsicRatio.width();
+}
+
+FloatSize LayoutSVGImage::calculateObjectSize()
+{
+    ImageResource* cachedImage = m_imageResource->cachedImage();
+    if (!cachedImage || cachedImage->errorOccurred())
+        return FloatSize();
+
+    FloatSize intrinsicSize = FloatSize(cachedImage->getImage()->size());
+    if (styleRef().width().isAuto() && styleRef().height().isAuto())
+        return intrinsicSize;
+
+    if (styleRef().height().isAuto())
+        return FloatSize(m_objectBoundingBox.width(), resolveHeightForRatio(m_objectBoundingBox.width(), intrinsicSize));
+
+    if (styleRef().width().isAuto())
+        return FloatSize(resolveWidthForRatio(m_objectBoundingBox.height(), intrinsicSize), m_objectBoundingBox.height());
+
+    return FloatSize();

[fs, 2016/09/14 11:31:52]

This is unreachable? Maybe just assert styleRef().width().isAuto() and return
that size instead?

[Shanmuga Pandi, 2016/09/14 13:15:36]

Done.

+}
+
+bool LayoutSVGImage::updateBoundingBox()
 {
     FloatRect oldBoundaries = m_objectBoundingBox;
 
@@ -71,9 +100,19 @@ void LayoutSVGImage::updateBoundingBox()
         lengthContext.valueForLength(styleRef().svgStyle().y(), styleRef(), SVGLengthMode::Height),
         lengthContext.valueForLength(styleRef().width(), styleRef(), SVGLengthMode::Width),
         lengthContext.valueForLength(styleRef().height(), styleRef(), SVGLengthMode::Height));
+
+    if (styleRef().width().isAuto() || styleRef().height().isAuto()) {
+        FloatSize intrinsicSize = calculateObjectSize();
+        if (styleRef().width().isAuto())

[fs, 2016/09/14 11:31:52]

This branching looks redundant - couldn't this just do:

m_objectBoundingBox.setSize(calculateObjectSize());

? (Might need to return m_objectBoundingBox.size() in the error-case in
calculateObjectSize.)

[Shanmuga Pandi, 2016/09/14 13:15:36]

Done.

+            m_objectBoundingBox.setWidth(intrinsicSize.width());
+        if (styleRef().height().isAuto())
+            m_objectBoundingBox.setHeight(intrinsicSize.height());
+    }
     m_needsBoundariesUpdate |= oldBoundaries != m_objectBoundingBox;
     if (element())
         element()->setNeedsResizeObserverUpdate();
+
+    return oldBoundaries.size() != m_objectBoundingBox.size();
 }
 
 void LayoutSVGImage::layout()
@@ -148,6 +187,11 @@ void LayoutSVGImage::imageChanged(WrappedImagePtr, const IntRect*)
     // representation of this image/layout object.
     LayoutSVGResourceContainer::markForLayoutAndParentResourceInvalidation(this, false);
 
+    if (styleRef().width().isAuto() || styleRef().height().isAuto()) {
+        if (updateBoundingBox())
+            setNeedsLayout(LayoutInvalidationReason::SizeChanged);
+    }
+
     setShouldDoFullPaintInvalidation();
 }