diff --git a/layout/generic/nsBlockFrame.cpp b/layout/generic/nsBlockFrame.cpp
index 22d6d0cbf974..438fa7f26d90 100644
--- a/layout/generic/nsBlockFrame.cpp
+++ b/layout/generic/nsBlockFrame.cpp
@@ -3546,7 +3546,7 @@ nsBlockFrame::ReflowInlineFrames(nsBlockReflowState& aState,
         // no longer makes sense.  Now we always allocate on the stack.
         nsLineLayout lineLayout(aState.mPresContext,
                                 aState.mReflowState.mFloatManager,
-                                &aState.mReflowState, &aLine);
+                                &aState.mReflowState, &aLine, nullptr);
         lineLayout.Init(&aState, aState.mMinLineHeight, aState.mLineNumber);
         if (forceBreakInFrame) {
           lineLayout.ForceBreakAtPosition(forceBreakInFrame, forceBreakOffset);
diff --git a/layout/generic/nsFirstLetterFrame.cpp b/layout/generic/nsFirstLetterFrame.cpp
index c0e68ddc87a2..8fa412ea033f 100644
--- a/layout/generic/nsFirstLetterFrame.cpp
+++ b/layout/generic/nsFirstLetterFrame.cpp
@@ -194,7 +194,7 @@ nsFirstLetterFrame::Reflow(nsPresContext*          aPresContext,
     WritingMode kidWritingMode = GetWritingMode(kid);
     LogicalSize kidAvailSize = availSize.ConvertTo(kidWritingMode, wm);
     nsHTMLReflowState rs(aPresContext, aReflowState, kid, kidAvailSize);
-    nsLineLayout ll(aPresContext, nullptr, &aReflowState, nullptr);
+    nsLineLayout ll(aPresContext, nullptr, &aReflowState, nullptr, nullptr);
 
     ll.BeginLineReflow(bp.IStart(wm), bp.BStart(wm),
                        availSize.ISize(wm), NS_UNCONSTRAINEDSIZE,
diff --git a/layout/generic/nsLineLayout.cpp b/layout/generic/nsLineLayout.cpp
index 404f5a828651..9d252101a005 100644
--- a/layout/generic/nsLineLayout.cpp
+++ b/layout/generic/nsLineLayout.cpp
@@ -51,10 +51,12 @@ using namespace mozilla;
 nsLineLayout::nsLineLayout(nsPresContext* aPresContext,
                            nsFloatManager* aFloatManager,
                            const nsHTMLReflowState* aOuterReflowState,
-                           const nsLineList::iterator* aLine)
+                           const nsLineList::iterator* aLine,
+                           nsLineLayout* aBaseLineLayout)
   : mPresContext(aPresContext),
     mFloatManager(aFloatManager),
     mBlockReflowState(aOuterReflowState),
+    mBaseLineLayout(aBaseLineLayout ? aBaseLineLayout->mBaseLineLayout : this),
     mLastOptionalBreakFrame(nullptr),
     mForceBreakFrame(nullptr),
     mBlockRS(nullptr),/* XXX temporary */
diff --git a/layout/generic/nsLineLayout.h b/layout/generic/nsLineLayout.h
index eb89a83931b9..4a8edad644ed 100644
--- a/layout/generic/nsLineLayout.h
+++ b/layout/generic/nsLineLayout.h
@@ -29,10 +29,15 @@ struct nsStyleText;
 
 class nsLineLayout {
 public:
+  /**
+   * @param aBaseLineLayout the nsLineLayout for ruby base,
+   * nullptr if no separate base nsLineLayout is needed.
+   */
   nsLineLayout(nsPresContext* aPresContext,
                nsFloatManager* aFloatManager,
                const nsHTMLReflowState* aOuterReflowState,
-               const nsLineList::iterator* aLine);
+               const nsLineList::iterator* aLine,
+               nsLineLayout* aBaseLineLayout);
   ~nsLineLayout();
 
   void Init(nsBlockReflowState* aState, nscoord aMinLineBSize,
@@ -346,6 +351,14 @@ protected:
   const nsStyleText* mStyleText; // for the block
   const nsHTMLReflowState* mBlockReflowState;
 
+  // The line layout for the base text. It is usually same as |this|.
+  // It becomes different when the current line layout is for ruby
+  // annotations. All line layouts share the same base line layout
+  // when they are associated. The base line layout is responsible
+  // for managing the life cycle of per-frame data and per-span data,
+  // and handling floats.
+  nsLineLayout* const mBaseLineLayout;
+
   nsIFrame* mLastOptionalBreakFrame;
   nsIFrame* mForceBreakFrame;
   
diff --git a/layout/generic/nsRubyBaseContainerFrame.cpp b/layout/generic/nsRubyBaseContainerFrame.cpp
index 499cf8cda679..765330553698 100644
--- a/layout/generic/nsRubyBaseContainerFrame.cpp
+++ b/layout/generic/nsRubyBaseContainerFrame.cpp
@@ -319,7 +319,7 @@ nsRubyBaseContainerFrame::Reflow(nsPresContext* aPresContext,
     reflowStates.AppendElement(reflowState);
     reflowStateArray->AppendElement(reflowState);
     nsLineLayout* lineLayout = new nsLineLayout(
-      aPresContext, reflowState->mFloatManager, reflowState, nullptr);
+      aPresContext, reflowState->mFloatManager, reflowState, nullptr, nullptr);
     lineLayouts.AppendElement(lineLayout);
 
     // Line number is useless for ruby text