Bug 981116: Convert nsFlexContainerFrame boolean member-var into frame state bit. r=heycam

layout/generic/nsFlexContainerFrame.cpp

@@ -1457,7 +1457,8 @@ nsFlexContainerFrame::SanityCheckAnonymousFlexItems() const
                "but it isn't");
     if (child->StyleContext()->GetPseudo() ==
         nsCSSAnonBoxes::anonymousFlexItem) {
-      MOZ_ASSERT(!prevChildWasAnonFlexItem || mChildrenHaveBeenReordered,
+      MOZ_ASSERT(!prevChildWasAnonFlexItem ||
+                 HasAnyStateBits(NS_STATE_FLEX_CHILDREN_REORDERED),
                  "two anon flex items in a row (shouldn't happen, unless our "
                  "children have been reordered with the 'order' property)");
 
@@ -2740,9 +2741,11 @@ nsFlexContainerFrame::Reflow(nsPresContext*           aPresContext,
   // operations need to use a fancier LEQ function that also takes DOM order
   // into account, so that we can honor the spec's requirement that frames w/
   // equal "order" values are laid out in DOM order.
-  if (!mChildrenHaveBeenReordered) {
-    mChildrenHaveBeenReordered =
-      SortChildrenIfNeeded<IsOrderLEQ>();
+
+  if (!HasAnyStateBits(NS_STATE_FLEX_CHILDREN_REORDERED)) {
+    if (SortChildrenIfNeeded<IsOrderLEQ>()) {
+      AddStateBits(NS_STATE_FLEX_CHILDREN_REORDERED);
+    }
   } else {
     SortChildrenIfNeeded<IsOrderLEQWithDOMFallback>();
   }

layout/generic/nsFlexContainerFrame.h

@@ -20,6 +20,7 @@ typedef nsContainerFrame nsFlexContainerFrameSuper;
 template <class T> class nsTArray;
 
 class nsFlexContainerFrame : public nsFlexContainerFrameSuper {
+public:
   NS_DECL_FRAMEARENA_HELPERS
   NS_DECL_QUERYFRAME_TARGET(nsFlexContainerFrame)
   NS_DECL_QUERYFRAME
@@ -28,7 +29,6 @@ class nsFlexContainerFrame : public nsFlexContainerFrameSuper {
   friend nsIFrame* NS_NewFlexContainerFrame(nsIPresShell* aPresShell,
                                             nsStyleContext* aContext);
 
-public:
   // Forward-decls of helper classes
   class FlexItem;
   class FlexLine;
@@ -60,8 +60,7 @@ public:
 protected:
   // Protected constructor & destructor
   nsFlexContainerFrame(nsStyleContext* aContext) :
-    nsFlexContainerFrameSuper(aContext),
-    mChildrenHaveBeenReordered(false)
+    nsFlexContainerFrameSuper(aContext)
   {}
   virtual ~nsFlexContainerFrame();
 

layout/generic/nsFrameState.cpp

@@ -10,6 +10,7 @@
 #include "nsBlockFrame.h"
 #include "nsBoxFrame.h"
 #include "nsBulletFrame.h"
+#include "nsFlexContainerFrame.h"
 #include "nsGfxScrollFrame.h"
 #include "nsIFrame.h"
 #include "nsISVGChildFrame.h"

layout/generic/nsFrameStateBits.h

@@ -284,6 +284,14 @@ FRAME_STATE_BIT(Box, 60, NS_FRAME_MOUSE_THROUGH_ALWAYS)
 FRAME_STATE_BIT(Box, 61, NS_FRAME_MOUSE_THROUGH_NEVER)
 
 
+// == Frame state bits that apply to flex container frames ====================
+
+FRAME_STATE_GROUP(FlexContainer, nsFlexContainerFrame)
+
+// Set for a flex container whose children have been reordered due to 'order'.
+// (Means that we have to be more thorough about checking them for sortedness.)
+FRAME_STATE_BIT(FlexContainer, 20, NS_STATE_FLEX_CHILDREN_REORDERED)
+
 // == Frame state bits that apply to SVG frames ===============================
 
 FRAME_STATE_GROUP(SVG, nsISVGChildFrame)