Bug 1144096 part 7 - [css-grid] Don't create PageBreakFrames inside a Grid container. The container will handle forced breaks on its items. r=dholbert

layout/base/nsCSSFrameConstructor.cpp

@@ -5757,6 +5757,8 @@ nsCSSFrameConstructor::AddFrameConstructionItemsInternal(nsFrameConstructorState
     (aFlags & ITEM_ALLOW_PAGE_BREAK) &&
     aState.mPresContext->IsPaginated() &&
     !display->IsAbsolutelyPositionedStyle() &&
+    !(aParentFrame &&
+      aParentFrame->GetType() == nsGkAtoms::gridContainerFrame) &&
     !(bits & FCDATA_IS_TABLE_PART) &&
     !(bits & FCDATA_IS_SVG_TEXT);