Don't paint below image's baseline unless it is selected.

Source/core/rendering/RenderReplaced.cpp

Index: Source/core/rendering/RenderReplaced.cpp
diff --git a/Source/core/rendering/RenderReplaced.cpp b/Source/core/rendering/RenderReplaced.cpp
index 353f974bcd0a68e8ae1361e7457ee17ef4d388dc..dcad512a47dc149e9bd4a2ca4f187f478b32d543 100644
--- a/Source/core/rendering/RenderReplaced.cpp
+++ b/Source/core/rendering/RenderReplaced.cpp
@@ -575,7 +575,15 @@ void RenderReplaced::setSelectionState(SelectionState state)
     // The selection state for our containing block hierarchy is updated by the base class call.
     RenderBox::setSelectionState(state);
 
-    if (inlineBoxWrapper() && canUpdateSelectionOnRootLineBoxes())
+    if (!inlineBoxWrapper())
+        return;
+
+    // We only include the space below the baseline in our layer's cached repaint rect if the
+    // image is selected. Since the selection state has changed update the rect.
+    if (hasLayer())
+        layer()->repainter().computeRepaintRects(containerForRepaint());

[Julien - ping for review, 2014/05/02 00:23:35]

I would expect this to fail with repaint-after-layout as we disable
RenderLayerRepainter.

In repaint-after-layout, you need to update the previous repaint rectangle (and
the previous position from the repaint container).

[rhogan, 2014/05/02 15:36:27]

If the layer-based repainter goes away then it will just get the correct rect
from clippedOverflowRectForRepaint() in
RenderObject::repaintAfterLayoutIfNeeded().

If I've misunderstood you could you point me in the right direction though?

+
+    if (canUpdateSelectionOnRootLineBoxes())
         inlineBoxWrapper()->root().setHasSelectedChildren(isSelected());
 }
 
@@ -602,24 +610,4 @@ bool RenderReplaced::isSelected() const
     return false;
 }
 
-LayoutRect RenderReplaced::clippedOverflowRectForRepaint(const RenderLayerModelObject* repaintContainer) const
-{
-    if (style()->visibility() != VISIBLE && !enclosingLayer()->hasVisibleContent())
-        return LayoutRect();
-
-    // The selectionRect can project outside of the overflowRect, so take their union
-    // for repainting to avoid selection painting glitches.
-    LayoutRect r = unionRect(localSelectionRect(false), visualOverflowRect());
-
-    RenderView* v = view();
-    if (!RuntimeEnabledFeatures::repaintAfterLayoutEnabled() && v) {
-        // FIXME: layoutDelta needs to be applied in parts before/after transforms and
-        // repaint containers. https://bugs.webkit.org/show_bug.cgi?id=23308
-        r.move(v->layoutDelta());
-    }
-
-    computeRectForRepaint(repaintContainer, r);
-    return r;
-}
-
 }