Add CSS image-orientation: from-image

Source/core/layout/compositing/CompositedDeprecatedPaintLayerMapping.cpp

Index: Source/core/layout/compositing/CompositedDeprecatedPaintLayerMapping.cpp
diff --git a/Source/core/layout/compositing/CompositedDeprecatedPaintLayerMapping.cpp b/Source/core/layout/compositing/CompositedDeprecatedPaintLayerMapping.cpp
index 44fafb8bfeaa6d0bd913355f295ce68f3aae8b88..f6684338c523ea097fcffaccf00d9274ecbbce6c 100644
--- a/Source/core/layout/compositing/CompositedDeprecatedPaintLayerMapping.cpp
+++ b/Source/core/layout/compositing/CompositedDeprecatedPaintLayerMapping.cpp
@@ -57,6 +57,7 @@
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/fonts/FontCache.h"
 #include "platform/geometry/TransformState.h"
+#include "platform/graphics/BitmapImage.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/paint/ClipDisplayItem.h"
 #include "platform/graphics/paint/DisplayItemList.h"
@@ -1851,7 +1852,11 @@ bool CompositedDeprecatedPaintLayerMapping::isDirectlyCompositedImage() const
             return false;
 
         Image* image = cachedImage->imageForLayoutObject(imageLayoutObject);
-        return image->isBitmapImage();
+        if (!image->isBitmapImage())
+            return false;
+
+        return imageLayoutObject->style()->respectImageOrientation() != RespectImageOrientation
+            || toBitmapImage(image)->size() == toBitmapImage(image)->sizeRespectingOrientation();

[Noel Gordon, 2015/06/12 16:21:04]

The first part of the clause looks right to me.  Bust it out into a separate if
statement.

The second part is interesting. If an image is orientated by 180 deg, the
orientated size and the natural size() are the same. So how is that rotation
sent to the GPU? I don't think ImageLayer supports that, nor do I see a change
to ImageLayer in your patch.  /curious I expect the GPU will just draw your
image un-orientated -> bug.

[rwlbuis, 2015/06/15 17:21:52]

Done.
Will experiment a bit with that, you could be right...

     }
 
     return false;