diff --git a/layout/generic/ReflowInput.cpp b/layout/generic/ReflowInput.cpp
index 80ca187df6ab..967066723162 100644
--- a/layout/generic/ReflowInput.cpp
+++ b/layout/generic/ReflowInput.cpp
@@ -2540,7 +2540,7 @@ SizeComputationInput::InitOffsets(WritingMode aWM,
                                   const nsMargin* aPadding,
                                   const nsStyleDisplay* aDisplay)
 {
-  DISPLAY_INIT_OFFSETS(mFrame, this, aPercentBasis, aWM, aBorder, aPadding);
+  DISPLAY_INIT_OFFSETS(mFrame, this, aPercentBasis, aBorder, aPadding);
 
   // Since we are in reflow, we don't need to store these properties anymore
   // unless they are dependent on width, in which case we store the new value.
diff --git a/layout/generic/ReflowInput.h b/layout/generic/ReflowInput.h
index 748ec676820f..d568996ceda3 100644
--- a/layout/generic/ReflowInput.h
+++ b/layout/generic/ReflowInput.h
@@ -247,7 +247,6 @@ public:
                                      nsIFrame* aFrame,
                                      SizeComputationInput* aState,
                                      const mozilla::LogicalSize& aPercentBasis,
-                                     WritingMode aCBWritingMode,
                                      const nsMargin* aBorder,
                                      const nsMargin* aPadding);
   static void DisplayInitOffsetsExit(nsIFrame* aFrame,
diff --git a/layout/generic/nsFrame.cpp b/layout/generic/nsFrame.cpp
index ee5414585923..3fdde880bf27 100644
--- a/layout/generic/nsFrame.cpp
+++ b/layout/generic/nsFrame.cpp
@@ -10918,9 +10918,8 @@ DR_init_constraints_cookie::~DR_init_constraints_cookie()
 
 DR_init_offsets_cookie::DR_init_offsets_cookie(
                      nsIFrame*                aFrame,
-                     SizeComputationInput*    aState,
+                     SizeComputationInput*        aState,
                      const LogicalSize&       aPercentBasis,
-                     WritingMode              aCBWritingMode,
                      const nsMargin*          aMargin,
                      const nsMargin*          aPadding)
   : mFrame(aFrame)
@@ -10928,9 +10927,8 @@ DR_init_offsets_cookie::DR_init_offsets_cookie(
 {
   MOZ_COUNT_CTOR(DR_init_offsets_cookie);
   mValue = SizeComputationInput::DisplayInitOffsetsEnter(mFrame, mState,
-                                                         aPercentBasis,
-                                                         aCBWritingMode,
-                                                         aMargin, aPadding);
+                                                     aPercentBasis,
+                                                     aMargin, aPadding);
 }
 
 DR_init_offsets_cookie::~DR_init_offsets_cookie()
@@ -11880,7 +11878,6 @@ ReflowInput::DisplayInitConstraintsExit(nsIFrame* aFrame,
 SizeComputationInput::DisplayInitOffsetsEnter(nsIFrame* aFrame,
                                           SizeComputationInput* aState,
                                           const LogicalSize& aPercentBasis,
-                                          WritingMode aCBWritingMode,
                                           const nsMargin* aBorder,
                                           const nsMargin* aPadding)
 {
@@ -11897,10 +11894,9 @@ SizeComputationInput::DisplayInitOffsetsEnter(nsIFrame* aFrame,
 
     char horizPctBasisStr[16];
     char vertPctBasisStr[16];
-    DR_state->PrettyUC(aPercentBasis.ISize(aCBWritingMode),
-                       horizPctBasisStr, 16);
-    DR_state->PrettyUC(aPercentBasis.BSize(aCBWritingMode),
-                       vertPctBasisStr, 16);
+    WritingMode wm = aState->GetWritingMode();
+    DR_state->PrettyUC(aPercentBasis.ISize(wm), horizPctBasisStr, 16);
+    DR_state->PrettyUC(aPercentBasis.BSize(wm), vertPctBasisStr, 16);
     printf("InitOffsets pct_basis=%s,%s", horizPctBasisStr, vertPctBasisStr);
 
     DR_state->PrintMargin("b", aBorder);
diff --git a/layout/generic/nsFrame.h b/layout/generic/nsFrame.h
index 5dd1ab14f7fd..7c342449ad32 100644
--- a/layout/generic/nsFrame.h
+++ b/layout/generic/nsFrame.h
@@ -865,7 +865,6 @@ public:
   struct DR_init_offsets_cookie {
     DR_init_offsets_cookie(nsIFrame* aFrame, mozilla::SizeComputationInput* aState,
                            const mozilla::LogicalSize& aPercentBasis,
-                           mozilla::WritingMode aCBWritingMode,
                            const nsMargin* aBorder,
                            const nsMargin* aPadding);
     ~DR_init_offsets_cookie();
@@ -904,10 +903,8 @@ public:
                                  dr_bdr, dr_pad)                           \
   DR_init_constraints_cookie dr_cookie(dr_frame, dr_state, dr_cbw, dr_cbh, \
                                        dr_bdr, dr_pad)
-#define DISPLAY_INIT_OFFSETS(dr_frame, dr_state, dr_pb, dr_cbwm, dr_bdr,      \
-                             dr_pad)                                          \
-  DR_init_offsets_cookie dr_cookie(dr_frame, dr_state, dr_pb, dr_cbwm,        \
-                             dr_bdr, dr_pad)
+#define DISPLAY_INIT_OFFSETS(dr_frame, dr_state, dr_pb, dr_bdr, dr_pad)  \
+  DR_init_offsets_cookie dr_cookie(dr_frame, dr_state, dr_pb, dr_bdr, dr_pad)
 #define DISPLAY_INIT_TYPE(dr_frame, dr_result) \
   DR_init_type_cookie dr_cookie(dr_frame, dr_result)