Bug 654641. Make nsDisplaySolidColor::GetBounds reflect any snapping that's going on. r=tnikkel

layout/base/nsDisplayList.cpp

@@ -828,8 +828,32 @@ PRBool nsDisplayItem::RecomputeVisibility(nsDisplayListBuilder* aBuilder,
   return PR_TRUE;
 }
 
-void nsDisplaySolidColor::Paint(nsDisplayListBuilder* aBuilder,
-                                nsRenderingContext* aCtx) {
+// Note that even if the rectangle we draw and snap is smaller than aRect,
+// it's OK to call this to get a bounding rect for what we'll draw, because
+// snapping a rectangle which is contained in R always gives you a
+// rectangle which is contained in the snapped R.
+static nsRect
+SnapBounds(PRBool aSnappingEnabled, nsPresContext* aPresContext,
+           const nsRect& aRect) {
+  nsRect r = aRect;
+  if (aSnappingEnabled) {
+    nscoord appUnitsPerDevPixel = aPresContext->AppUnitsPerDevPixel();
+    r = r.ToNearestPixels(appUnitsPerDevPixel).ToAppUnits(appUnitsPerDevPixel);
+  }
+  return r;
+}
+
+nsRect
+nsDisplaySolidColor::GetBounds(nsDisplayListBuilder* aBuilder)
+{
+  nsPresContext* presContext = mFrame->PresContext();
+  return SnapBounds(mSnappingEnabled, presContext, mBounds);
+}
+
+void
+nsDisplaySolidColor::Paint(nsDisplayListBuilder* aBuilder,
+                           nsRenderingContext* aCtx)
+{
   aCtx->SetColor(mColor);
   aCtx->FillRect(mVisibleRect);
 }
@@ -1025,21 +1049,6 @@ nsDisplayBackground::ComputeVisibility(nsDisplayListBuilder* aBuilder,
     nsCSSRendering::FindBackground(mFrame->PresContext(), mFrame, &bgSC);
 }
 
-// Note that even if the rectangle we draw and snap is smaller than aRect,
-// it's OK to call this to get a bounding rect for what we'll draw, because
-// snapping a rectangle which is contained in R always gives you a
-// rectangle which is contained in the snapped R.
-static nsRect
-SnapBounds(PRBool aSnappingEnabled, nsPresContext* aPresContext,
-           const nsRect& aRect) {
-  nsRect r = aRect;
-  if (aSnappingEnabled) {
-    nscoord appUnitsPerDevPixel = aPresContext->AppUnitsPerDevPixel();
-    r = r.ToNearestPixels(appUnitsPerDevPixel).ToAppUnits(appUnitsPerDevPixel);
-  }
-  return r;
-}
-
 nsRegion
 nsDisplayBackground::GetInsideClipRegion(nsPresContext* aPresContext,
                                          PRUint8 aClip, const nsRect& aRect)

layout/base/nsDisplayList.h

@@ -1457,7 +1457,8 @@ public:
                       const nsRect& aBounds, nscolor aColor,
                       PRBool aIsRootContentDocBackground = PR_FALSE)
     : nsDisplayItem(aBuilder, aFrame), mBounds(aBounds), mColor(aColor),
-      mIsRootContentDocBackground(aIsRootContentDocBackground) {
+      mIsRootContentDocBackground(aIsRootContentDocBackground),
+      mSnappingEnabled(aBuilder->IsSnappingEnabled() && !aBuilder->IsInTransform()) {
     NS_ASSERTION(NS_GET_A(aColor) > 0, "Don't create invisible nsDisplaySolidColors!");
     MOZ_COUNT_CTOR(nsDisplaySolidColor);
   }
@@ -1467,7 +1468,7 @@ public:
   }
 #endif
 
-  virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder) { return mBounds; }
+  virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder);
 
   virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
                                    PRBool* aOutTransparentBackground = nsnull) {
@@ -1504,6 +1505,7 @@ private:
   nsRect  mBounds;
   nscolor mColor;
   PRPackedBool mIsRootContentDocBackground;
+  PRPackedBool mSnappingEnabled;
 };
 
 /**