Invalidate the frame view when changing the background image of the document or body.

Source/core/frame/FrameView.cpp

Index: Source/core/frame/FrameView.cpp
diff --git a/Source/core/frame/FrameView.cpp b/Source/core/frame/FrameView.cpp
index d5bf83aa8aecf7602cb2c174a742c86203a68ac7..3ad0947e71f1b4ef984773e8cffca0bfab8784a9 100644
--- a/Source/core/frame/FrameView.cpp
+++ b/Source/core/frame/FrameView.cpp
@@ -991,8 +991,6 @@ void FrameView::layout(bool allowSubtree)
 
     layer->updateLayerPositionsAfterLayout();
 
-    if (m_doFullPaintInvalidation)
-        renderView()->compositor()->fullyInvalidatePaint();
     renderView()->compositor()->didLayout();
 
     m_layoutCount++;
@@ -1048,6 +1046,9 @@ void FrameView::invalidateTreeIfNeeded()
 
     PaintInvalidationState rootPaintInvalidationState(rootForPaintInvalidation);
 
+    if (m_doFullPaintInvalidation)
+        renderView()->compositor()->fullyInvalidatePaint();
+
     rootForPaintInvalidation.invalidateTreeIfNeeded(rootPaintInvalidationState);
 
     // Invalidate the paint of the frameviews scrollbars if needed
@@ -1058,6 +1059,7 @@ void FrameView::invalidateTreeIfNeeded()
     resetScrollbarDamage();
 
     m_doFullPaintInvalidation = false;
+
 #ifndef NDEBUG
     renderView()->assertSubtreeClearedPaintInvalidationState();
 #endif
@@ -1714,8 +1716,11 @@ void FrameView::scrollbarExistenceDidChange()
     // http://crbug.com/269692
     bool useOverlayScrollbars = ScrollbarTheme::theme()->usesOverlayScrollbars();
 
+    // FIXME: this call to layout() could be called within FrameView::layout(), but before performLayout(),
+    // causing double-layout.

[dsinclair, 2014/10/31 00:14:34]

Can you file a bug to track this?

[chrishtr, 2014/10/31 18:22:24]

Done.

     if (!useOverlayScrollbars && needsLayout())
         layout();
+    }

[dsinclair, 2014/10/31 00:14:34]

Don't think this should be here.

[chrishtr, 2014/10/31 18:22:24]

Done.

 
     if (renderView() && renderView()->usesCompositing()) {
         renderView()->compositor()->frameViewScrollbarsExistenceDidChange();