Bug 1008969 - part 1, Initialize the nsHTMLReflowState "frame type" correctly for display:grid/inline-grid. Add nsIFrame::IsFlexOrGridItem(), and use it to share some flexbox code in nsHTMLReflowState. r=dholbert

layout/base/nsDisplayList.cpp

@@ -1689,7 +1689,7 @@ nsDisplayItem::MaxActiveLayers()
 int32_t
 nsDisplayItem::ZIndex() const
 {
-  if (!mFrame->IsPositioned() && !mFrame->IsFlexItem())
+  if (!mFrame->IsPositioned() && !mFrame->IsFlexOrGridItem())
     return 0;
 
   const nsStylePosition* position = mFrame->StylePosition();

layout/generic/nsHTMLReflowState.cpp

@@ -141,9 +141,9 @@ nsCSSOffsetState::nsCSSOffsetState(nsIFrame *aFrame,
   , rendContext(aRenderingContext)
   , mWritingMode(aFrame->GetWritingMode())
 {
-  MOZ_ASSERT(!aFrame->IsFlexItem(),
+  MOZ_ASSERT(!aFrame->IsFlexOrGridItem(),
              "We're about to resolve vertical percent margin & padding "
-             "values against CB width, which is incorrect for flex items");
+             "values against CB width, which is incorrect for flex/grid items");
   InitOffsets(aContainingBlockWidth, aContainingBlockWidth, frame->GetType());
 }
 
@@ -717,6 +717,7 @@ nsHTMLReflowState::InitFrameType(nsIAtom* aFrameType)
     case NS_STYLE_DISPLAY_TABLE:
     case NS_STYLE_DISPLAY_TABLE_CAPTION:
     case NS_STYLE_DISPLAY_FLEX:
+    case NS_STYLE_DISPLAY_GRID:
       frameType = NS_CSS_FRAME_TYPE_BLOCK;
       break;
 
@@ -727,6 +728,7 @@ nsHTMLReflowState::InitFrameType(nsIAtom* aFrameType)
     case NS_STYLE_DISPLAY_INLINE_XUL_GRID:
     case NS_STYLE_DISPLAY_INLINE_STACK:
     case NS_STYLE_DISPLAY_INLINE_FLEX:
+    case NS_STYLE_DISPLAY_INLINE_GRID:
       frameType = NS_CSS_FRAME_TYPE_INLINE;
       break;
 
@@ -1873,7 +1875,7 @@ VerticalOffsetPercentBasis(const nsIFrame* aFrame,
                            nscoord aContainingBlockWidth,
                            nscoord aContainingBlockHeight)
 {
-  if (!aFrame->IsFlexItem()) {
+  if (!aFrame->IsFlexOrGridItem()) {
     return aContainingBlockWidth;
   }
 

layout/generic/nsIFrame.h

@@ -2931,6 +2931,10 @@ NS_PTR_TO_INT32(frame->Properties().Get(nsIFrame::ParagraphDepthProperty()))
    * Is this a flex item? (i.e. a non-abs-pos child of a flex container)
    */
   inline bool IsFlexItem() const;
+  /**
+   * Is this a flex or grid item? (i.e. a non-abs-pos child of a flex/grid container)
+   */
+  inline bool IsFlexOrGridItem() const;
 
   inline bool IsBlockInside() const;
   inline bool IsBlockOutside() const;

layout/generic/nsIFrameInlines.h

@@ -18,6 +18,18 @@ nsIFrame::IsFlexItem() const
     !(GetStateBits() & NS_FRAME_OUT_OF_FLOW);
 }
 
+bool
+nsIFrame::IsFlexOrGridItem() const
+{
+  if (mParent) {
+    nsIAtom* t = mParent->GetType();
+    return (t == nsGkAtoms::flexContainerFrame ||
+            t == nsGkAtoms::gridContainerFrame) &&
+      !(GetStateBits() & NS_FRAME_OUT_OF_FLOW);
+  }
+  return false;
+}
+
 bool
 nsIFrame::IsFloating() const
 {