Bug 1028216 - Backout 660cc013d558 (bug 952721) for causing b2g animation regressions.

layout/base/nsDisplayList.cpp

@@ -4749,26 +4749,26 @@ nsDisplayTransform::ShouldPrerenderTransformedContent(nsDisplayListBuilder* aBui
   }
 
   nsSize refSize = aBuilder->RootReferenceFrame()->GetSize();
-  // Only prerender if the transformed frame's size (in the reference
-  // frames coordinate space) is <= the reference frame size (~viewport),
-  // allowing a 1/8th fuzz factor for shadows, borders, etc.
+  // Only prerender if the transformed frame's size is <= the
+  // reference frame size (~viewport), allowing a 1/8th fuzz factor
+  // for shadows, borders, etc.
   refSize += nsSize(refSize.width / 8, refSize.height / 8);
-  nsRect frameRect = aFrame->GetVisualOverflowRectRelativeToSelf();
-
-  frameRect =
-    nsLayoutUtils::TransformFrameRectToAncestor(aFrame, frameRect,
-                                                aBuilder->RootReferenceFrame());
-
-  if (frameRect.Size() <= refSize) {
-    return true;
+  nsSize frameSize = aFrame->GetVisualOverflowRectRelativeToSelf().Size();
+  if (frameSize <= refSize) {
+    // Bug 717521 - pre-render max 4096 x 4096 device pixels.
+    nscoord max = aFrame->PresContext()->DevPixelsToAppUnits(4096);
+    nsRect visual = aFrame->GetVisualOverflowRect();
+    if (visual.width <= max && visual.height <= max) {
+      return true;
+    }
   }
 
   if (aLogAnimations) {
     nsCString message;
     message.AppendLiteral("Performance warning: Async animation disabled because frame size (");
-    message.AppendInt(nsPresContext::AppUnitsToIntCSSPixels(frameRect.width));
+    message.AppendInt(nsPresContext::AppUnitsToIntCSSPixels(frameSize.width));
     message.AppendLiteral(", ");
-    message.AppendInt(nsPresContext::AppUnitsToIntCSSPixels(frameRect.height));
+    message.AppendInt(nsPresContext::AppUnitsToIntCSSPixels(frameSize.height));
     message.AppendLiteral(") is bigger than the viewport (");
     message.AppendInt(nsPresContext::AppUnitsToIntCSSPixels(refSize.width));
     message.AppendLiteral(", ");