Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3453 insertions, 0 deletions

diff --git a/layout/generic/nsLineLayout.cpp b/layout/generic/nsLineLayout.cpp
new file mode 100644
index 0000000000..e072b981b2
--- /dev/null
+++ b/layout/generic/nsLineLayout.cpp
@@ -0,0 +1,3453 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* state and methods used while laying out a single line of a block frame */
+
+#include "nsLineLayout.h"
+
+#include "mozilla/ComputedStyle.h"
+#include "mozilla/SVGTextFrame.h"
+
+#include "LayoutLogging.h"
+#include "nsBlockFrame.h"
+#include "nsFontMetrics.h"
+#include "nsStyleConsts.h"
+#include "nsContainerFrame.h"
+#include "nsFloatManager.h"
+#include "nsPresContext.h"
+#include "nsGkAtoms.h"
+#include "nsIContent.h"
+#include "nsLayoutUtils.h"
+#include "nsTextFrame.h"
+#include "nsStyleStructInlines.h"
+#include "nsBidiPresUtils.h"
+#include "nsRubyFrame.h"
+#include "nsRubyTextFrame.h"
+#include "RubyUtils.h"
+#include <algorithm>
+
+#ifdef DEBUG
+#  undef NOISY_INLINEDIR_ALIGN
+#  undef NOISY_BLOCKDIR_ALIGN
+#  undef NOISY_REFLOW
+#  undef REALLY_NOISY_REFLOW
+#  undef NOISY_PUSHING
+#  undef REALLY_NOISY_PUSHING
+#  undef NOISY_CAN_PLACE_FRAME
+#  undef NOISY_TRIM
+#  undef REALLY_NOISY_TRIM
+#endif
+
+using namespace mozilla;
+
+//----------------------------------------------------------------------
+
+nsLineLayout::nsLineLayout(nsPresContext* aPresContext,
+                           nsFloatManager* aFloatManager,
+                           const ReflowInput& aLineContainerRI,
+                           const nsLineList::iterator* aLine,
+                           nsLineLayout* aBaseLineLayout)
+    : mPresContext(aPresContext),
+      mFloatManager(aFloatManager),
+      mLineContainerRI(aLineContainerRI),
+      mBaseLineLayout(aBaseLineLayout),
+      mLastOptionalBreakFrame(nullptr),
+      mForceBreakFrame(nullptr),
+      mLastOptionalBreakPriority(gfxBreakPriority::eNoBreak),
+      mLastOptionalBreakFrameOffset(-1),
+      mForceBreakFrameOffset(-1),
+      mMinLineBSize(0),
+      mTextIndent(0),
+      mMaxStartBoxBSize(0),
+      mMaxEndBoxBSize(0),
+      mFinalLineBSize(0),
+      mFirstLetterStyleOK(false),
+      mIsTopOfPage(false),
+      mImpactedByFloats(false),
+      mLastFloatWasLetterFrame(false),
+      mLineIsEmpty(false),
+      mLineEndsInBR(false),
+      mNeedBackup(false),
+      mInFirstLine(false),
+      mGotLineBox(false),
+      mInFirstLetter(false),
+      mHasMarker(false),
+      mDirtyNextLine(false),
+      mLineAtStart(false),
+      mHasRuby(false),
+      mSuppressLineWrap(LineContainerFrame()->IsInSVGTextSubtree())
+#ifdef DEBUG
+      ,
+      mSpansAllocated(0),
+      mSpansFreed(0),
+      mFramesAllocated(0),
+      mFramesFreed(0)
+#endif
+{
+  NS_ASSERTION(aFloatManager || LineContainerFrame()->IsLetterFrame(),
+               "float manager should be present");
+  MOZ_ASSERT(
+      !!mBaseLineLayout == LineContainerFrame()->IsRubyTextContainerFrame(),
+      "Only ruby text container frames have a different base line layout");
+  MOZ_COUNT_CTOR(nsLineLayout);
+
+  // Stash away some style data that we need
+  nsBlockFrame* blockFrame = do_QueryFrame(LineContainerFrame());
+  mStyleText = blockFrame ? blockFrame->StyleTextForLineLayout()
+                          : LineContainerFrame()->StyleText();
+
+  mLineNumber = 0;
+  mTotalPlacedFrames = 0;
+  mBStartEdge = 0;
+  mTrimmableISize = 0;
+
+  mInflationMinFontSize =
+      nsLayoutUtils::InflationMinFontSizeFor(LineContainerFrame());
+
+  // Instead of always pre-initializing the free-lists for frames and
+  // spans, we do it on demand so that situations that only use a few
+  // frames and spans won't waste a lot of time in unneeded
+  // initialization.
+  mFrameFreeList = nullptr;
+  mSpanFreeList = nullptr;
+
+  mCurrentSpan = mRootSpan = nullptr;
+  mSpanDepth = 0;
+
+  if (aLine) {
+    mGotLineBox = true;
+    mLineBox = *aLine;
+  }
+}
+
+nsLineLayout::~nsLineLayout() {
+  MOZ_COUNT_DTOR(nsLineLayout);
+
+  NS_ASSERTION(nullptr == mRootSpan, "bad line-layout user");
+}
+
+// Find out if the frame has a non-null prev-in-flow, i.e., whether it
+// is a continuation.
+inline bool HasPrevInFlow(nsIFrame* aFrame) {
+  nsIFrame* prevInFlow = aFrame->GetPrevInFlow();
+  return prevInFlow != nullptr;
+}
+
+void nsLineLayout::BeginLineReflow(nscoord aICoord, nscoord aBCoord,
+                                   nscoord aISize, nscoord aBSize,
+                                   bool aImpactedByFloats, bool aIsTopOfPage,
+                                   WritingMode aWritingMode,
+                                   const nsSize& aContainerSize) {
+  NS_ASSERTION(nullptr == mRootSpan, "bad linelayout user");
+  LAYOUT_WARN_IF_FALSE(aISize != NS_UNCONSTRAINEDSIZE,
+                       "have unconstrained width; this should only result from "
+                       "very large sizes, not attempts at intrinsic width "
+                       "calculation");
+#ifdef DEBUG
+  if ((aISize != NS_UNCONSTRAINEDSIZE) && ABSURD_SIZE(aISize) &&
+      !LineContainerFrame()->GetParent()->IsAbsurdSizeAssertSuppressed()) {
+    LineContainerFrame()->ListTag(stdout);
+    printf(": Init: bad caller: width WAS %d(0x%x)\n", aISize, aISize);
+  }
+  if ((aBSize != NS_UNCONSTRAINEDSIZE) && ABSURD_SIZE(aBSize) &&
+      !LineContainerFrame()->GetParent()->IsAbsurdSizeAssertSuppressed()) {
+    LineContainerFrame()->ListTag(stdout);
+    printf(": Init: bad caller: height WAS %d(0x%x)\n", aBSize, aBSize);
+  }
+#endif
+#ifdef NOISY_REFLOW
+  LineContainerFrame()->ListTag(stdout);
+  printf(": BeginLineReflow: %d,%d,%d,%d impacted=%s %s\n", aICoord, aBCoord,
+         aISize, aBSize, aImpactedByFloats ? "true" : "false",
+         aIsTopOfPage ? "top-of-page" : "");
+#endif
+#ifdef DEBUG
+  mSpansAllocated = mSpansFreed = mFramesAllocated = mFramesFreed = 0;
+#endif
+
+  mFirstLetterStyleOK = false;
+  mIsTopOfPage = aIsTopOfPage;
+  mImpactedByFloats = aImpactedByFloats;
+  mTotalPlacedFrames = 0;
+  if (!mBaseLineLayout) {
+    mLineIsEmpty = true;
+    mLineAtStart = true;
+  } else {
+    mLineIsEmpty = false;
+    mLineAtStart = false;
+  }
+  mLineEndsInBR = false;
+  mSpanDepth = 0;
+  mMaxStartBoxBSize = mMaxEndBoxBSize = 0;
+
+  if (mGotLineBox) {
+    mLineBox->ClearHasMarker();
+  }
+
+  PerSpanData* psd = NewPerSpanData();
+  mCurrentSpan = mRootSpan = psd;
+  psd->mReflowInput = &mLineContainerRI;
+  psd->mIStart = aICoord;
+  psd->mICoord = aICoord;
+  psd->mIEnd = aICoord + aISize;
+  mContainerSize = aContainerSize;
+
+  mBStartEdge = aBCoord;
+
+  psd->mNoWrap = !mStyleText->WhiteSpaceCanWrapStyle() || mSuppressLineWrap;
+  psd->mWritingMode = aWritingMode;
+
+  // If this is the first line of a block then see if the text-indent
+  // property amounts to anything.
+
+  if (0 == mLineNumber && !HasPrevInFlow(LineContainerFrame())) {
+    nscoord pctBasis = mLineContainerRI.ComputedISize();
+    mTextIndent = mStyleText->mTextIndent.Resolve(pctBasis);
+    psd->mICoord += mTextIndent;
+  }
+
+  PerFrameData* pfd = NewPerFrameData(LineContainerFrame());
+  pfd->mAscent = 0;
+  pfd->mSpan = psd;
+  psd->mFrame = pfd;
+  nsIFrame* frame = LineContainerFrame();
+  if (frame->IsRubyTextContainerFrame()) {
+    // Ruby text container won't be reflowed via ReflowFrame, hence the
+    // relative positioning information should be recorded here.
+    MOZ_ASSERT(mBaseLineLayout != this);
+    pfd->mIsRelativelyOrStickyPos =
+        mLineContainerRI.mStyleDisplay->IsRelativelyOrStickyPositionedStyle();
+    if (pfd->mIsRelativelyOrStickyPos) {
+      MOZ_ASSERT(mLineContainerRI.GetWritingMode() == pfd->mWritingMode,
+                 "mLineContainerRI.frame == frame, "
+                 "hence they should have identical writing mode");
+      pfd->mOffsets =
+          mLineContainerRI.ComputedLogicalOffsets(pfd->mWritingMode);
+    }
+  }
+}
+
+void nsLineLayout::EndLineReflow() {
+#ifdef NOISY_REFLOW
+  LineContainerFrame()->ListTag(stdout);
+  printf(": EndLineReflow: width=%d\n",
+         mRootSpan->mICoord - mRootSpan->mIStart);
+#endif
+
+  NS_ASSERTION(!mBaseLineLayout ||
+                   (!mSpansAllocated && !mSpansFreed && !mSpanFreeList &&
+                    !mFramesAllocated && !mFramesFreed && !mFrameFreeList),
+               "Allocated frames or spans on non-base line layout?");
+  MOZ_ASSERT(mRootSpan == mCurrentSpan);
+
+  UnlinkFrame(mRootSpan->mFrame);
+  mCurrentSpan = mRootSpan = nullptr;
+
+  NS_ASSERTION(mSpansAllocated == mSpansFreed, "leak");
+  NS_ASSERTION(mFramesAllocated == mFramesFreed, "leak");
+
+#if 0
+  static int32_t maxSpansAllocated = NS_LINELAYOUT_NUM_SPANS;
+  static int32_t maxFramesAllocated = NS_LINELAYOUT_NUM_FRAMES;
+  if (mSpansAllocated > maxSpansAllocated) {
+    printf("XXX: saw a line with %d spans\n", mSpansAllocated);
+    maxSpansAllocated = mSpansAllocated;
+  }
+  if (mFramesAllocated > maxFramesAllocated) {
+    printf("XXX: saw a line with %d frames\n", mFramesAllocated);
+    maxFramesAllocated = mFramesAllocated;
+  }
+#endif
+}
+
+// XXX swtich to a single mAvailLineWidth that we adjust as each frame
+// on the line is placed. Each span can still have a per-span mICoord that
+// tracks where a child frame is going in its span; they don't need a
+// per-span mIStart?
+
+void nsLineLayout::UpdateBand(WritingMode aWM,
+                              const LogicalRect& aNewAvailSpace,
+                              nsIFrame* aFloatFrame) {
+  WritingMode lineWM = mRootSpan->mWritingMode;
+  // need to convert to our writing mode, because we might have a different
+  // mode from the caller due to dir: auto
+  LogicalRect availSpace =
+      aNewAvailSpace.ConvertTo(lineWM, aWM, ContainerSize());
+#ifdef REALLY_NOISY_REFLOW
+  printf(
+      "nsLL::UpdateBand %d, %d, %d, %d, (converted to %d, %d, %d, %d); "
+      "frame=%p\n  will set mImpacted to true\n",
+      aNewAvailSpace.IStart(aWM), aNewAvailSpace.BStart(aWM),
+      aNewAvailSpace.ISize(aWM), aNewAvailSpace.BSize(aWM),
+      availSpace.IStart(lineWM), availSpace.BStart(lineWM),
+      availSpace.ISize(lineWM), availSpace.BSize(lineWM), aFloatFrame);
+#endif
+#ifdef DEBUG
+  if ((availSpace.ISize(lineWM) != NS_UNCONSTRAINEDSIZE) &&
+      ABSURD_SIZE(availSpace.ISize(lineWM)) &&
+      !LineContainerFrame()->GetParent()->IsAbsurdSizeAssertSuppressed()) {
+    LineContainerFrame()->ListTag(stdout);
+    printf(": UpdateBand: bad caller: ISize WAS %d(0x%x)\n",
+           availSpace.ISize(lineWM), availSpace.ISize(lineWM));
+  }
+  if ((availSpace.BSize(lineWM) != NS_UNCONSTRAINEDSIZE) &&
+      ABSURD_SIZE(availSpace.BSize(lineWM)) &&
+      !LineContainerFrame()->GetParent()->IsAbsurdSizeAssertSuppressed()) {
+    LineContainerFrame()->ListTag(stdout);
+    printf(": UpdateBand: bad caller: BSize WAS %d(0x%x)\n",
+           availSpace.BSize(lineWM), availSpace.BSize(lineWM));
+  }
+#endif
+
+  // Compute the difference between last times width and the new width
+  NS_WARNING_ASSERTION(
+      mRootSpan->mIEnd != NS_UNCONSTRAINEDSIZE &&
+          availSpace.ISize(lineWM) != NS_UNCONSTRAINEDSIZE,
+      "have unconstrained inline size; this should only result from very large "
+      "sizes, not attempts at intrinsic width calculation");
+  // The root span's mIStart moves to aICoord
+  nscoord deltaICoord = availSpace.IStart(lineWM) - mRootSpan->mIStart;
+  // The inline size of all spans changes by this much (the root span's
+  // mIEnd moves to aICoord + aISize, its new inline size is aISize)
+  nscoord deltaISize =
+      availSpace.ISize(lineWM) - (mRootSpan->mIEnd - mRootSpan->mIStart);
+#ifdef NOISY_REFLOW
+  LineContainerFrame()->ListTag(stdout);
+  printf(": UpdateBand: %d,%d,%d,%d deltaISize=%d deltaICoord=%d\n",
+         availSpace.IStart(lineWM), availSpace.BStart(lineWM),
+         availSpace.ISize(lineWM), availSpace.BSize(lineWM), deltaISize,
+         deltaICoord);
+#endif
+
+  // Update the root span position
+  mRootSpan->mIStart += deltaICoord;
+  mRootSpan->mIEnd += deltaICoord;
+  mRootSpan->mICoord += deltaICoord;
+
+  // Now update the right edges of the open spans to account for any
+  // change in available space width
+  for (PerSpanData* psd = mCurrentSpan; psd; psd = psd->mParent) {
+    psd->mIEnd += deltaISize;
+    psd->mContainsFloat = true;
+#ifdef NOISY_REFLOW
+    printf("  span %p: oldIEnd=%d newIEnd=%d\n", psd, psd->mIEnd - deltaISize,
+           psd->mIEnd);
+#endif
+  }
+  NS_ASSERTION(mRootSpan->mContainsFloat &&
+                   mRootSpan->mIStart == availSpace.IStart(lineWM) &&
+                   mRootSpan->mIEnd == availSpace.IEnd(lineWM),
+               "root span was updated incorrectly?");
+
+  // Update frame bounds
+  // Note: Only adjust the outermost frames (the ones that are direct
+  // children of the block), not the ones in the child spans. The reason
+  // is simple: the frames in the spans have coordinates local to their
+  // parent therefore they are moved when their parent span is moved.
+  if (deltaICoord != 0) {
+    for (PerFrameData* pfd = mRootSpan->mFirstFrame; pfd; pfd = pfd->mNext) {
+      pfd->mBounds.IStart(lineWM) += deltaICoord;
+    }
+  }
+
+  mBStartEdge = availSpace.BStart(lineWM);
+  mImpactedByFloats = true;
+
+  mLastFloatWasLetterFrame = aFloatFrame->IsLetterFrame();
+}
+
+nsLineLayout::PerSpanData* nsLineLayout::NewPerSpanData() {
+  nsLineLayout* outerLineLayout = GetOutermostLineLayout();
+  PerSpanData* psd = outerLineLayout->mSpanFreeList;
+  if (!psd) {
+    void* mem = outerLineLayout->mArena.Allocate(sizeof(PerSpanData));
+    psd = reinterpret_cast<PerSpanData*>(mem);
+  } else {
+    outerLineLayout->mSpanFreeList = psd->mNextFreeSpan;
+  }
+  psd->mParent = nullptr;
+  psd->mFrame = nullptr;
+  psd->mFirstFrame = nullptr;
+  psd->mLastFrame = nullptr;
+  psd->mContainsFloat = false;
+  psd->mHasNonemptyContent = false;
+
+#ifdef DEBUG
+  outerLineLayout->mSpansAllocated++;
+#endif
+  return psd;
+}
+
+void nsLineLayout::BeginSpan(nsIFrame* aFrame,
+                             const ReflowInput* aSpanReflowInput,
+                             nscoord aIStart, nscoord aIEnd,
+                             nscoord* aBaseline) {
+  NS_ASSERTION(aIEnd != NS_UNCONSTRAINEDSIZE,
+               "should no longer be using unconstrained sizes");
+#ifdef NOISY_REFLOW
+  nsIFrame::IndentBy(stdout, mSpanDepth + 1);
+  aFrame->ListTag(stdout);
+  printf(": BeginSpan leftEdge=%d rightEdge=%d\n", aIStart, aIEnd);
+#endif
+
+  PerSpanData* psd = NewPerSpanData();
+  // Link up span frame's pfd to point to its child span data
+  PerFrameData* pfd = mCurrentSpan->mLastFrame;
+  NS_ASSERTION(pfd->mFrame == aFrame, "huh?");
+  pfd->mSpan = psd;
+
+  // Init new span
+  psd->mFrame = pfd;
+  psd->mParent = mCurrentSpan;
+  psd->mReflowInput = aSpanReflowInput;
+  psd->mIStart = aIStart;
+  psd->mICoord = aIStart;
+  psd->mIEnd = aIEnd;
+  psd->mBaseline = aBaseline;
+
+  nsIFrame* frame = aSpanReflowInput->mFrame;
+  psd->mNoWrap = !frame->StyleText()->WhiteSpaceCanWrap(frame) ||
+                 mSuppressLineWrap || frame->Style()->ShouldSuppressLineBreak();
+  psd->mWritingMode = aSpanReflowInput->GetWritingMode();
+
+  // Switch to new span
+  mCurrentSpan = psd;
+  mSpanDepth++;
+}
+
+nscoord nsLineLayout::EndSpan(nsIFrame* aFrame) {
+  NS_ASSERTION(mSpanDepth > 0, "end-span without begin-span");
+#ifdef NOISY_REFLOW
+  nsIFrame::IndentBy(stdout, mSpanDepth);
+  aFrame->ListTag(stdout);
+  printf(": EndSpan width=%d\n", mCurrentSpan->mICoord - mCurrentSpan->mIStart);
+#endif
+  PerSpanData* psd = mCurrentSpan;
+  MOZ_ASSERT(psd->mParent, "We never call this on the root");
+
+  if (psd->mNoWrap && !psd->mParent->mNoWrap) {
+    FlushNoWrapFloats();
+  }
+
+  nscoord iSizeResult = psd->mLastFrame ? (psd->mICoord - psd->mIStart) : 0;
+
+  mSpanDepth--;
+  mCurrentSpan->mReflowInput = nullptr;  // no longer valid so null it out!
+  mCurrentSpan = mCurrentSpan->mParent;
+  return iSizeResult;
+}
+
+void nsLineLayout::AttachFrameToBaseLineLayout(PerFrameData* aFrame) {
+  MOZ_ASSERT(mBaseLineLayout,
+             "This method must not be called in a base line layout.");
+
+  PerFrameData* baseFrame = mBaseLineLayout->LastFrame();
+  MOZ_ASSERT(aFrame && baseFrame);
+  MOZ_ASSERT(!aFrame->mIsLinkedToBase,
+             "The frame must not have been linked with the base");
+#ifdef DEBUG
+  LayoutFrameType baseType = baseFrame->mFrame->Type();
+  LayoutFrameType annotationType = aFrame->mFrame->Type();
+  MOZ_ASSERT((baseType == LayoutFrameType::RubyBaseContainer &&
+              annotationType == LayoutFrameType::RubyTextContainer) ||
+             (baseType == LayoutFrameType::RubyBase &&
+              annotationType == LayoutFrameType::RubyText));
+#endif
+
+  aFrame->mNextAnnotation = baseFrame->mNextAnnotation;
+  baseFrame->mNextAnnotation = aFrame;
+  aFrame->mIsLinkedToBase = true;
+}
+
+int32_t nsLineLayout::GetCurrentSpanCount() const {
+  NS_ASSERTION(mCurrentSpan == mRootSpan, "bad linelayout user");
+  int32_t count = 0;
+  PerFrameData* pfd = mRootSpan->mFirstFrame;
+  while (nullptr != pfd) {
+    count++;
+    pfd = pfd->mNext;
+  }
+  return count;
+}
+
+void nsLineLayout::SplitLineTo(int32_t aNewCount) {
+  NS_ASSERTION(mCurrentSpan == mRootSpan, "bad linelayout user");
+
+#ifdef REALLY_NOISY_PUSHING
+  printf("SplitLineTo %d (current count=%d); before:\n", aNewCount,
+         GetCurrentSpanCount());
+  DumpPerSpanData(mRootSpan, 1);
+#endif
+  PerSpanData* psd = mRootSpan;
+  PerFrameData* pfd = psd->mFirstFrame;
+  while (nullptr != pfd) {
+    if (--aNewCount == 0) {
+      // Truncate list at pfd (we keep pfd, but anything following is freed)
+      PerFrameData* next = pfd->mNext;
+      pfd->mNext = nullptr;
+      psd->mLastFrame = pfd;
+
+      // Now unlink all of the frames following pfd
+      UnlinkFrame(next);
+      break;
+    }
+    pfd = pfd->mNext;
+  }
+#ifdef NOISY_PUSHING
+  printf("SplitLineTo %d (current count=%d); after:\n", aNewCount,
+         GetCurrentSpanCount());
+  DumpPerSpanData(mRootSpan, 1);
+#endif
+}
+
+void nsLineLayout::PushFrame(nsIFrame* aFrame) {
+  PerSpanData* psd = mCurrentSpan;
+  NS_ASSERTION(psd->mLastFrame->mFrame == aFrame, "pushing non-last frame");
+
+#ifdef REALLY_NOISY_PUSHING
+  nsIFrame::IndentBy(stdout, mSpanDepth);
+  printf("PushFrame %p, before:\n", psd);
+  DumpPerSpanData(psd, 1);
+#endif
+
+  // Take the last frame off of the span's frame list
+  PerFrameData* pfd = psd->mLastFrame;
+  if (pfd == psd->mFirstFrame) {
+    // We are pushing away the only frame...empty the list
+    psd->mFirstFrame = nullptr;
+    psd->mLastFrame = nullptr;
+  } else {
+    PerFrameData* prevFrame = pfd->mPrev;
+    prevFrame->mNext = nullptr;
+    psd->mLastFrame = prevFrame;
+  }
+
+  // Now unlink the frame
+  MOZ_ASSERT(!pfd->mNext);
+  UnlinkFrame(pfd);
+#ifdef NOISY_PUSHING
+  nsIFrame::IndentBy(stdout, mSpanDepth);
+  printf("PushFrame: %p after:\n", psd);
+  DumpPerSpanData(psd, 1);
+#endif
+}
+
+void nsLineLayout::UnlinkFrame(PerFrameData* pfd) {
+  while (nullptr != pfd) {
+    PerFrameData* next = pfd->mNext;
+    if (pfd->mIsLinkedToBase) {
+      // This frame is linked to a ruby base, and should not be freed
+      // now. Just unlink it from the span. It will be freed when its
+      // base frame gets unlinked.
+      pfd->mNext = pfd->mPrev = nullptr;
+      pfd = next;
+      continue;
+    }
+
+    // It is a ruby base frame. If there are any annotations
+    // linked to this frame, free them first.
+    PerFrameData* annotationPFD = pfd->mNextAnnotation;
+    while (annotationPFD) {
+      PerFrameData* nextAnnotation = annotationPFD->mNextAnnotation;
+      MOZ_ASSERT(
+          annotationPFD->mNext == nullptr && annotationPFD->mPrev == nullptr,
+          "PFD in annotations should have been unlinked.");
+      FreeFrame(annotationPFD);
+      annotationPFD = nextAnnotation;
+    }
+
+    FreeFrame(pfd);
+    pfd = next;
+  }
+}
+
+void nsLineLayout::FreeFrame(PerFrameData* pfd) {
+  if (nullptr != pfd->mSpan) {
+    FreeSpan(pfd->mSpan);
+  }
+  nsLineLayout* outerLineLayout = GetOutermostLineLayout();
+  pfd->mNext = outerLineLayout->mFrameFreeList;
+  outerLineLayout->mFrameFreeList = pfd;
+#ifdef DEBUG
+  outerLineLayout->mFramesFreed++;
+#endif
+}
+
+void nsLineLayout::FreeSpan(PerSpanData* psd) {
+  // Unlink its frames
+  UnlinkFrame(psd->mFirstFrame);
+
+  nsLineLayout* outerLineLayout = GetOutermostLineLayout();
+  // Now put the span on the free list since it's free too
+  psd->mNextFreeSpan = outerLineLayout->mSpanFreeList;
+  outerLineLayout->mSpanFreeList = psd;
+#ifdef DEBUG
+  outerLineLayout->mSpansFreed++;
+#endif
+}
+
+bool nsLineLayout::IsZeroBSize() {
+  PerSpanData* psd = mCurrentSpan;
+  PerFrameData* pfd = psd->mFirstFrame;
+  while (nullptr != pfd) {
+    if (0 != pfd->mBounds.BSize(psd->mWritingMode)) {
+      return false;
+    }
+    pfd = pfd->mNext;
+  }
+  return true;
+}
+
+nsLineLayout::PerFrameData* nsLineLayout::NewPerFrameData(nsIFrame* aFrame) {
+  nsLineLayout* outerLineLayout = GetOutermostLineLayout();
+  PerFrameData* pfd = outerLineLayout->mFrameFreeList;
+  if (!pfd) {
+    void* mem = outerLineLayout->mArena.Allocate(sizeof(PerFrameData));
+    pfd = reinterpret_cast<PerFrameData*>(mem);
+  } else {
+    outerLineLayout->mFrameFreeList = pfd->mNext;
+  }
+  pfd->mSpan = nullptr;
+  pfd->mNext = nullptr;
+  pfd->mPrev = nullptr;
+  pfd->mNextAnnotation = nullptr;
+  pfd->mFrame = aFrame;
+
+  // all flags default to false
+  pfd->mIsRelativelyOrStickyPos = false;
+  pfd->mIsTextFrame = false;
+  pfd->mIsNonEmptyTextFrame = false;
+  pfd->mIsNonWhitespaceTextFrame = false;
+  pfd->mIsLetterFrame = false;
+  pfd->mRecomputeOverflow = false;
+  pfd->mIsMarker = false;
+  pfd->mSkipWhenTrimmingWhitespace = false;
+  pfd->mIsEmpty = false;
+  pfd->mIsPlaceholder = false;
+  pfd->mIsLinkedToBase = false;
+
+  pfd->mWritingMode = aFrame->GetWritingMode();
+  WritingMode lineWM = mRootSpan->mWritingMode;
+  pfd->mBounds = LogicalRect(lineWM);
+  pfd->mOverflowAreas.Clear();
+  pfd->mMargin = LogicalMargin(lineWM);
+  pfd->mBorderPadding = LogicalMargin(lineWM);
+  pfd->mOffsets = LogicalMargin(pfd->mWritingMode);
+
+  pfd->mJustificationInfo = JustificationInfo();
+  pfd->mJustificationAssignment = JustificationAssignment();
+
+#ifdef DEBUG
+  pfd->mBlockDirAlign = 0xFF;
+  outerLineLayout->mFramesAllocated++;
+#endif
+  return pfd;
+}
+
+bool nsLineLayout::LineIsBreakable() const {
+  // XXX mTotalPlacedFrames should go away and we should just use
+  // mLineIsEmpty here instead
+  if ((0 != mTotalPlacedFrames) || mImpactedByFloats) {
+    return true;
+  }
+  return false;
+}
+
+// Checks all four sides for percentage units.  This means it should
+// only be used for things (margin, padding) where percentages on top
+// and bottom depend on the *width* just like percentages on left and
+// right.
+template <typename T>
+static bool HasPercentageUnitSide(const StyleRect<T>& aSides) {
+  return aSides.Any([](const auto& aLength) { return aLength.HasPercent(); });
+}
+
+static bool IsPercentageAware(const nsIFrame* aFrame, WritingMode aWM) {
+  NS_ASSERTION(aFrame, "null frame is not allowed");
+
+  LayoutFrameType fType = aFrame->Type();
+  if (fType == LayoutFrameType::Text) {
+    // None of these things can ever be true for text frames.
+    return false;
+  }
+
+  // Some of these things don't apply to non-replaced inline frames
+  // (that is, fType == LayoutFrameType::Inline), but we won't bother making
+  // things unnecessarily complicated, since they'll probably be set
+  // quite rarely.
+
+  const nsStyleMargin* margin = aFrame->StyleMargin();
+  if (HasPercentageUnitSide(margin->mMargin)) {
+    return true;
+  }
+
+  const nsStylePadding* padding = aFrame->StylePadding();
+  if (HasPercentageUnitSide(padding->mPadding)) {
+    return true;
+  }
+
+  // Note that borders can't be aware of percentages
+
+  const nsStylePosition* pos = aFrame->StylePosition();
+
+  if ((pos->ISizeDependsOnContainer(aWM) && !pos->ISize(aWM).IsAuto()) ||
+      pos->MaxISizeDependsOnContainer(aWM) ||
+      pos->MinISizeDependsOnContainer(aWM) ||
+      pos->mOffset.GetIStart(aWM).HasPercent() ||
+      pos->mOffset.GetIEnd(aWM).HasPercent()) {
+    return true;
+  }
+
+  if (pos->ISize(aWM).IsAuto()) {
+    // We need to check for frames that shrink-wrap when they're auto
+    // width.
+    const nsStyleDisplay* disp = aFrame->StyleDisplay();
+    if ((disp->DisplayOutside() == StyleDisplayOutside::Inline &&
+         (disp->DisplayInside() == StyleDisplayInside::FlowRoot ||
+          disp->DisplayInside() == StyleDisplayInside::Table)) ||
+        fType == LayoutFrameType::HTMLButtonControl ||
+        fType == LayoutFrameType::GfxButtonControl ||
+        fType == LayoutFrameType::FieldSet ||
+        fType == LayoutFrameType::ComboboxDisplay) {
+      return true;
+    }
+
+    // Per CSS 2.1, section 10.3.2:
+    //   If 'height' and 'width' both have computed values of 'auto' and
+    //   the element has an intrinsic ratio but no intrinsic height or
+    //   width and the containing block's width does not itself depend
+    //   on the replaced element's width, then the used value of 'width'
+    //   is calculated from the constraint equation used for
+    //   block-level, non-replaced elements in normal flow.
+    nsIFrame* f = const_cast<nsIFrame*>(aFrame);
+    if (f->GetAspectRatio() &&
+        // Some percents are treated like 'auto', so check != coord
+        !pos->BSize(aWM).ConvertsToLength()) {
+      const IntrinsicSize& intrinsicSize = f->GetIntrinsicSize();
+      if (!intrinsicSize.width && !intrinsicSize.height) {
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+void nsLineLayout::ReflowFrame(nsIFrame* aFrame, nsReflowStatus& aReflowStatus,
+                               ReflowOutput* aMetrics, bool& aPushedFrame) {
+  // Initialize OUT parameter
+  aPushedFrame = false;
+
+  PerFrameData* pfd = NewPerFrameData(aFrame);
+  PerSpanData* psd = mCurrentSpan;
+  psd->AppendFrame(pfd);
+
+#ifdef REALLY_NOISY_REFLOW
+  nsIFrame::IndentBy(stdout, mSpanDepth);
+  printf("%p: Begin ReflowFrame pfd=%p ", psd, pfd);
+  aFrame->ListTag(stdout);
+  printf("\n");
+#endif
+
+  if (mCurrentSpan == mRootSpan) {
+    pfd->mFrame->RemoveProperty(nsIFrame::LineBaselineOffset());
+  } else {
+#ifdef DEBUG
+    bool hasLineOffset;
+    pfd->mFrame->GetProperty(nsIFrame::LineBaselineOffset(), &hasLineOffset);
+    NS_ASSERTION(!hasLineOffset,
+                 "LineBaselineOffset was set but was not expected");
+#endif
+  }
+
+  mJustificationInfo = JustificationInfo();
+
+  // Stash copies of some of the computed state away for later
+  // (block-direction alignment, for example)
+  WritingMode frameWM = pfd->mWritingMode;
+  WritingMode lineWM = mRootSpan->mWritingMode;
+
+  // NOTE: While the inline direction coordinate remains relative to the
+  // parent span, the block direction coordinate is fixed at the top
+  // edge for the line. During VerticalAlignFrames we will repair this
+  // so that the block direction coordinate is properly set and relative
+  // to the appropriate span.
+  pfd->mBounds.IStart(lineWM) = psd->mICoord;
+  pfd->mBounds.BStart(lineWM) = mBStartEdge;
+
+  // We want to guarantee that we always make progress when
+  // formatting. Therefore, if the object being placed on the line is
+  // too big for the line, but it is the only thing on the line and is not
+  // impacted by a float, then we go ahead and place it anyway. (If the line
+  // is impacted by one or more floats, then it is safe to break because
+  // we can move the line down below float(s).)
+  //
+  // Capture this state *before* we reflow the frame in case it clears
+  // the state out. We need to know how to treat the current frame
+  // when breaking.
+  bool notSafeToBreak = LineIsEmpty() && !mImpactedByFloats;
+
+  // Figure out whether we're talking about a textframe here
+  LayoutFrameType frameType = aFrame->Type();
+  const bool isText = frameType == LayoutFrameType::Text;
+
+  // Inline-ish and text-ish things don't compute their width;
+  // everything else does.  We need to give them an available width that
+  // reflects the space left on the line.
+  LAYOUT_WARN_IF_FALSE(psd->mIEnd != NS_UNCONSTRAINEDSIZE,
+                       "have unconstrained width; this should only result from "
+                       "very large sizes, not attempts at intrinsic width "
+                       "calculation");
+  nscoord availableSpaceOnLine = psd->mIEnd - psd->mICoord;
+
+  // Setup reflow input for reflowing the frame
+  Maybe<ReflowInput> reflowInputHolder;
+  if (!isText) {
+    // Compute the available size for the frame. This available width
+    // includes room for the side margins.
+    // For now, set the available block-size to unconstrained always.
+    LogicalSize availSize = mLineContainerRI.ComputedSize(frameWM);
+    availSize.BSize(frameWM) = NS_UNCONSTRAINEDSIZE;
+    reflowInputHolder.emplace(mPresContext, *psd->mReflowInput, aFrame,
+                              availSize);
+    ReflowInput& reflowInput = *reflowInputHolder;
+    reflowInput.mLineLayout = this;
+    reflowInput.mFlags.mIsTopOfPage = mIsTopOfPage;
+    if (reflowInput.ComputedISize() == NS_UNCONSTRAINEDSIZE) {
+      reflowInput.SetAvailableISize(availableSpaceOnLine);
+    }
+    pfd->mMargin = reflowInput.ComputedLogicalMargin(lineWM);
+    pfd->mBorderPadding = reflowInput.ComputedLogicalBorderPadding(lineWM);
+    pfd->mIsRelativelyOrStickyPos =
+        reflowInput.mStyleDisplay->IsRelativelyOrStickyPositionedStyle();
+    if (pfd->mIsRelativelyOrStickyPos) {
+      pfd->mOffsets = reflowInput.ComputedLogicalOffsets(frameWM);
+    }
+
+    // Calculate whether the the frame should have a start margin and
+    // subtract the margin from the available width if necessary.
+    // The margin will be applied to the starting inline coordinates of
+    // the frame in CanPlaceFrame() after reflowing the frame.
+    AllowForStartMargin(pfd, reflowInput);
+  }
+  // if isText(), no need to propagate NS_FRAME_IS_DIRTY from the parent,
+  // because reflow doesn't look at the dirty bits on the frame being reflowed.
+
+  // See if this frame depends on the inline-size of its containing block.
+  // If so, disable resize reflow optimizations for the line.  (Note that,
+  // to be conservative, we do this if we *try* to fit a frame on a
+  // line, even if we don't succeed.)  (Note also that we can only make
+  // this IsPercentageAware check *after* we've constructed our
+  // ReflowInput, because that construction may be what forces aFrame
+  // to lazily initialize its (possibly-percent-valued) intrinsic size.)
+  if (mGotLineBox && IsPercentageAware(aFrame, lineWM)) {
+    mLineBox->DisableResizeReflowOptimization();
+  }
+
+  // Note that we don't bother positioning the frame yet, because we're probably
+  // going to end up moving it when we do the block-direction alignment.
+
+  // Adjust float manager coordinate system for the frame.
+  ReflowOutput reflowOutput(lineWM);
+#ifdef DEBUG
+  reflowOutput.ISize(lineWM) = nscoord(0xdeadbeef);
+  reflowOutput.BSize(lineWM) = nscoord(0xdeadbeef);
+#endif
+  nscoord tI = pfd->mBounds.LineLeft(lineWM, ContainerSize());
+  nscoord tB = pfd->mBounds.BStart(lineWM);
+  mFloatManager->Translate(tI, tB);
+
+  int32_t savedOptionalBreakOffset;
+  gfxBreakPriority savedOptionalBreakPriority;
+  nsIFrame* savedOptionalBreakFrame = GetLastOptionalBreakPosition(
+      &savedOptionalBreakOffset, &savedOptionalBreakPriority);
+
+  if (!isText) {
+    aFrame->Reflow(mPresContext, reflowOutput, *reflowInputHolder,
+                   aReflowStatus);
+  } else {
+    static_cast<nsTextFrame*>(aFrame)->ReflowText(
+        *this, availableSpaceOnLine,
+        psd->mReflowInput->mRenderingContext->GetDrawTarget(), reflowOutput,
+        aReflowStatus);
+  }
+
+  pfd->mJustificationInfo = mJustificationInfo;
+  mJustificationInfo = JustificationInfo();
+
+  // See if the frame is a placeholderFrame and if it is process
+  // the float. At the same time, check if the frame has any non-collapsed-away
+  // content.
+  bool placedFloat = false;
+  bool isEmpty;
+  if (frameType == LayoutFrameType::None) {
+    isEmpty = pfd->mFrame->IsEmpty();
+  } else if (LayoutFrameType::Placeholder == frameType) {
+    isEmpty = true;
+    pfd->mIsPlaceholder = true;
+    pfd->mSkipWhenTrimmingWhitespace = true;
+    nsIFrame* outOfFlowFrame = nsLayoutUtils::GetFloatFromPlaceholder(aFrame);
+    if (outOfFlowFrame) {
+      if (psd->mNoWrap &&
+          // We can always place floats in an empty line.
+          !LineIsEmpty() &&
+          // We always place floating letter frames. This kinda sucks. They'd
+          // usually fall into the LineIsEmpty() check anyway, except when
+          // there's something like a ::marker before or what not. We actually
+          // need to place them now, because they're pretty nasty and they
+          // create continuations that are in flow and not a kid of the
+          // previous continuation's parent. We don't want the deferred reflow
+          // of the letter frame to kill a continuation after we've stored it
+          // in the line layout data structures. See bug 1490281 to fix the
+          // underlying issue. When that's fixed this check should be removed.
+          !outOfFlowFrame->IsLetterFrame() &&
+          !GetOutermostLineLayout()->mBlockRS->mFlags.mCanHaveOverflowMarkers) {
+        // We'll do this at the next break opportunity.
+        RecordNoWrapFloat(outOfFlowFrame);
+      } else {
+        placedFloat = TryToPlaceFloat(outOfFlowFrame);
+      }
+    }
+  } else if (isText) {
+    // Note non-empty text-frames for inline frame compatibility hackery
+    pfd->mIsTextFrame = true;
+    auto* textFrame = static_cast<nsTextFrame*>(pfd->mFrame);
+    isEmpty = !textFrame->HasNoncollapsedCharacters();
+    if (!isEmpty) {
+      pfd->mIsNonEmptyTextFrame = true;
+      pfd->mIsNonWhitespaceTextFrame =
+          !textFrame->GetContent()->TextIsOnlyWhitespace();
+    }
+  } else if (LayoutFrameType::Br == frameType) {
+    pfd->mSkipWhenTrimmingWhitespace = true;
+    isEmpty = false;
+  } else {
+    if (LayoutFrameType::Letter == frameType) {
+      pfd->mIsLetterFrame = true;
+    }
+    if (pfd->mSpan) {
+      isEmpty = !pfd->mSpan->mHasNonemptyContent && pfd->mFrame->IsSelfEmpty();
+    } else {
+      isEmpty = pfd->mFrame->IsEmpty();
+    }
+  }
+  pfd->mIsEmpty = isEmpty;
+
+  mFloatManager->Translate(-tI, -tB);
+
+  NS_ASSERTION(reflowOutput.ISize(lineWM) >= 0, "bad inline size");
+  NS_ASSERTION(reflowOutput.BSize(lineWM) >= 0, "bad block size");
+  if (reflowOutput.ISize(lineWM) < 0) {
+    reflowOutput.ISize(lineWM) = 0;
+  }
+  if (reflowOutput.BSize(lineWM) < 0) {
+    reflowOutput.BSize(lineWM) = 0;
+  }
+
+#ifdef DEBUG
+  // Note: break-before means ignore the reflow metrics since the
+  // frame will be reflowed another time.
+  if (!aReflowStatus.IsInlineBreakBefore()) {
+    if ((ABSURD_SIZE(reflowOutput.ISize(lineWM)) ||
+         ABSURD_SIZE(reflowOutput.BSize(lineWM))) &&
+        !LineContainerFrame()->GetParent()->IsAbsurdSizeAssertSuppressed()) {
+      printf("nsLineLayout: ");
+      aFrame->ListTag(stdout);
+      printf(" metrics=%d,%d!\n", reflowOutput.Width(), reflowOutput.Height());
+    }
+    if ((reflowOutput.Width() == nscoord(0xdeadbeef)) ||
+        (reflowOutput.Height() == nscoord(0xdeadbeef))) {
+      printf("nsLineLayout: ");
+      aFrame->ListTag(stdout);
+      printf(" didn't set w/h %d,%d!\n", reflowOutput.Width(),
+             reflowOutput.Height());
+    }
+  }
+#endif
+
+  // Unlike with non-inline reflow, the overflow area here does *not*
+  // include the accumulation of the frame's bounds and its inline
+  // descendants' bounds. Nor does it include the outline area; it's
+  // just the union of the bounds of any absolute children. That is
+  // added in later by nsLineLayout::ReflowInlineFrames.
+  pfd->mOverflowAreas = reflowOutput.mOverflowAreas;
+
+  pfd->mBounds.ISize(lineWM) = reflowOutput.ISize(lineWM);
+  pfd->mBounds.BSize(lineWM) = reflowOutput.BSize(lineWM);
+
+  // Size the frame, but |RelativePositionFrames| will size the view.
+  aFrame->SetRect(lineWM, pfd->mBounds, ContainerSizeForSpan(psd));
+
+  // Tell the frame that we're done reflowing it
+  aFrame->DidReflow(mPresContext, isText ? nullptr : reflowInputHolder.ptr());
+
+  if (aMetrics) {
+    *aMetrics = reflowOutput;
+  }
+
+  if (!aReflowStatus.IsInlineBreakBefore()) {
+    // If frame is complete and has a next-in-flow, we need to delete
+    // them now. Do not do this when a break-before is signaled because
+    // the frame is going to get reflowed again (and may end up wanting
+    // a next-in-flow where it ends up).
+    if (aReflowStatus.IsComplete()) {
+      if (nsIFrame* kidNextInFlow = aFrame->GetNextInFlow()) {
+        // Remove all of the childs next-in-flows. Make sure that we ask
+        // the right parent to do the removal (it's possible that the
+        // parent is not this because we are executing pullup code)
+        FrameDestroyContext context(aFrame->PresShell());
+        kidNextInFlow->GetParent()->DeleteNextInFlowChild(context,
+                                                          kidNextInFlow, true);
+      }
+    }
+
+    // Check whether this frame breaks up text runs. All frames break up text
+    // runs (hence return false here) except for text frames and inline
+    // containers.
+    bool continuingTextRun = aFrame->CanContinueTextRun();
+
+    // Clear any residual mTrimmableISize if this isn't a text frame
+    if (!continuingTextRun && !pfd->mSkipWhenTrimmingWhitespace) {
+      mTrimmableISize = 0;
+    }
+
+    // See if we can place the frame. If we can't fit it, then we
+    // return now.
+    bool optionalBreakAfterFits;
+    NS_ASSERTION(isText || !reflowInputHolder->mStyleDisplay->IsFloating(
+                               reflowInputHolder->mFrame),
+                 "How'd we get a floated inline frame? "
+                 "The frame ctor should've dealt with this.");
+    if (CanPlaceFrame(pfd, notSafeToBreak, continuingTextRun,
+                      savedOptionalBreakFrame != nullptr, reflowOutput,
+                      aReflowStatus, &optionalBreakAfterFits)) {
+      if (!isEmpty) {
+        psd->mHasNonemptyContent = true;
+        mLineIsEmpty = false;
+        if (!pfd->mSpan) {
+          // nonempty leaf content has been placed
+          mLineAtStart = false;
+        }
+        if (LayoutFrameType::Ruby == frameType) {
+          mHasRuby = true;
+          SyncAnnotationBounds(pfd);
+        }
+      }
+
+      // Place the frame, updating aBounds with the final size and
+      // location.  Then apply the bottom+right margins (as
+      // appropriate) to the frame.
+      PlaceFrame(pfd, reflowOutput);
+      PerSpanData* span = pfd->mSpan;
+      if (span) {
+        // The frame we just finished reflowing is an inline
+        // container.  It needs its child frames aligned in the block direction,
+        // so do most of it now.
+        VerticalAlignFrames(span);
+      }
+
+      if (!continuingTextRun && !psd->mNoWrap) {
+        if (!LineIsEmpty() || placedFloat) {
+          // record soft break opportunity after this content that can't be
+          // part of a text run. This is not a text frame so we know
+          // that offset INT32_MAX means "after the content".
+          if ((!aFrame->IsPlaceholderFrame() || LineIsEmpty()) &&
+              NotifyOptionalBreakPosition(aFrame, INT32_MAX,
+                                          optionalBreakAfterFits,
+                                          gfxBreakPriority::eNormalBreak)) {
+            // If this returns true then we are being told to actually break
+            // here.
+            aReflowStatus.SetInlineLineBreakAfter();
+          }
+        }
+      }
+    } else {
+      PushFrame(aFrame);
+      aPushedFrame = true;
+      // Undo any saved break positions that the frame might have told us about,
+      // since we didn't end up placing it
+      RestoreSavedBreakPosition(savedOptionalBreakFrame,
+                                savedOptionalBreakOffset,
+                                savedOptionalBreakPriority);
+    }
+  } else {
+    PushFrame(aFrame);
+    aPushedFrame = true;
+  }
+
+#ifdef REALLY_NOISY_REFLOW
+  nsIFrame::IndentBy(stdout, mSpanDepth);
+  printf("End ReflowFrame ");
+  aFrame->ListTag(stdout);
+  printf(" status=%x\n", aReflowStatus);
+#endif
+}
+
+void nsLineLayout::AllowForStartMargin(PerFrameData* pfd,
+                                       ReflowInput& aReflowInput) {
+  NS_ASSERTION(!aReflowInput.mStyleDisplay->IsFloating(aReflowInput.mFrame),
+               "How'd we get a floated inline frame? "
+               "The frame ctor should've dealt with this.");
+
+  WritingMode lineWM = mRootSpan->mWritingMode;
+
+  // Only apply start-margin on the first-in flow for inline frames,
+  // and make sure to not apply it to any inline other than the first
+  // in an ib split.  Note that the ib sibling (block-in-inline
+  // sibling) annotations only live on the first continuation, but we
+  // don't want to apply the start margin for later continuations
+  // anyway.  For box-decoration-break:clone we apply the start-margin
+  // on all continuations.
+  if ((pfd->mFrame->GetPrevContinuation() ||
+       pfd->mFrame->FrameIsNonFirstInIBSplit()) &&
+      aReflowInput.mStyleBorder->mBoxDecorationBreak ==
+          StyleBoxDecorationBreak::Slice) {
+    // Zero this out so that when we compute the max-element-width of
+    // the frame we will properly avoid adding in the starting margin.
+    pfd->mMargin.IStart(lineWM) = 0;
+  } else if (NS_UNCONSTRAINEDSIZE == aReflowInput.ComputedISize()) {
+    NS_WARNING_ASSERTION(
+        NS_UNCONSTRAINEDSIZE != aReflowInput.AvailableISize(),
+        "have unconstrained inline-size; this should only result from very "
+        "large sizes, not attempts at intrinsic inline-size calculation");
+    // For inline-ish and text-ish things (which don't compute widths
+    // in the reflow input), adjust available inline-size to account
+    // for the start margin. The end margin will be accounted for when
+    // we finish flowing the frame.
+    WritingMode wm = aReflowInput.GetWritingMode();
+    aReflowInput.SetAvailableISize(
+        aReflowInput.AvailableISize() -
+        pfd->mMargin.ConvertTo(wm, lineWM).IStart(wm));
+  }
+}
+
+nscoord nsLineLayout::GetCurrentFrameInlineDistanceFromBlock() {
+  PerSpanData* psd;
+  nscoord x = 0;
+  for (psd = mCurrentSpan; psd; psd = psd->mParent) {
+    x += psd->mICoord;
+  }
+  return x;
+}
+
+/**
+ * This method syncs bounds of ruby annotations and ruby annotation
+ * containers from their rect. It is necessary because:
+ * Containers are not part of the line in their levels, which means
+ * their bounds are not set properly before.
+ * Ruby annotations' position may have been changed when reflowing
+ * their containers.
+ */
+void nsLineLayout::SyncAnnotationBounds(PerFrameData* aRubyFrame) {
+  MOZ_ASSERT(aRubyFrame->mFrame->IsRubyFrame());
+  MOZ_ASSERT(aRubyFrame->mSpan);
+
+  PerSpanData* span = aRubyFrame->mSpan;
+  WritingMode lineWM = mRootSpan->mWritingMode;
+  for (PerFrameData* pfd = span->mFirstFrame; pfd; pfd = pfd->mNext) {
+    for (PerFrameData* rtc = pfd->mNextAnnotation; rtc;
+         rtc = rtc->mNextAnnotation) {
+      if (lineWM.IsOrthogonalTo(rtc->mFrame->GetWritingMode())) {
+        // Inter-character case: don't attempt to sync annotation bounds.
+        continue;
+      }
+      // When the annotation container is reflowed, the width of the
+      // ruby container is unknown so we use a dummy container size;
+      // in the case of RTL block direction, the final position will be
+      // fixed up later.
+      const nsSize dummyContainerSize;
+      LogicalRect rtcBounds(lineWM, rtc->mFrame->GetRect(), dummyContainerSize);
+      rtc->mBounds = rtcBounds;
+      nsSize rtcSize = rtcBounds.Size(lineWM).GetPhysicalSize(lineWM);
+      for (PerFrameData* rt = rtc->mSpan->mFirstFrame; rt; rt = rt->mNext) {
+        LogicalRect rtBounds = rt->mFrame->GetLogicalRect(lineWM, rtcSize);
+        MOZ_ASSERT(rt->mBounds.Size(lineWM) == rtBounds.Size(lineWM),
+                   "Size of the annotation should not have been changed");
+        rt->mBounds.SetOrigin(lineWM, rtBounds.Origin(lineWM));
+      }
+    }
+  }
+}
+
+/**
+ * See if the frame can be placed now that we know it's desired size.
+ * We can always place the frame if the line is empty. Note that we
+ * know that the reflow-status is not a break-before because if it was
+ * ReflowFrame above would have returned false, preventing this method
+ * from being called. The logic in this method assumes that.
+ *
+ * Note that there is no check against the Y coordinate because we
+ * assume that the caller will take care of that.
+ */
+bool nsLineLayout::CanPlaceFrame(PerFrameData* pfd, bool aNotSafeToBreak,
+                                 bool aFrameCanContinueTextRun,
+                                 bool aCanRollBackBeforeFrame,
+                                 ReflowOutput& aMetrics,
+                                 nsReflowStatus& aStatus,
+                                 bool* aOptionalBreakAfterFits) {
+  MOZ_ASSERT(pfd && pfd->mFrame, "bad args, null pointers for frame data");
+
+  *aOptionalBreakAfterFits = true;
+
+  WritingMode lineWM = mRootSpan->mWritingMode;
+  /*
+   * We want to only apply the end margin if we're the last continuation and
+   * either not in an {ib} split or the last inline in it.  In all other
+   * cases we want to zero it out.  That means zeroing it out if any of these
+   * conditions hold:
+   * 1) The frame is not complete (in this case it will get a next-in-flow)
+   * 2) The frame is complete but has a non-fluid continuation on its
+   *    continuation chain.  Note that if it has a fluid continuation, that
+   *    continuation will get destroyed later, so we don't want to drop the
+   *    end-margin in that case.
+   * 3) The frame is in an {ib} split and is not the last part.
+   *
+   * However, none of that applies if this is a letter frame (XXXbz why?)
+   *
+   * For box-decoration-break:clone we apply the end margin on all
+   * continuations (that are not letter frames).
+   */
+  if ((aStatus.IsIncomplete() ||
+       pfd->mFrame->LastInFlow()->GetNextContinuation() ||
+       pfd->mFrame->FrameIsNonLastInIBSplit()) &&
+      !pfd->mIsLetterFrame &&
+      pfd->mFrame->StyleBorder()->mBoxDecorationBreak ==
+          StyleBoxDecorationBreak::Slice) {
+    pfd->mMargin.IEnd(lineWM) = 0;
+  }
+
+  // Apply the start margin to the frame bounds.
+  nscoord startMargin = pfd->mMargin.IStart(lineWM);
+  nscoord endMargin = pfd->mMargin.IEnd(lineWM);
+
+  pfd->mBounds.IStart(lineWM) += startMargin;
+
+  PerSpanData* psd = mCurrentSpan;
+  if (psd->mNoWrap) {
+    // When wrapping is off, everything fits.
+    return true;
+  }
+
+#ifdef NOISY_CAN_PLACE_FRAME
+  if (psd->mFrame) {
+    psd->mFrame->mFrame->ListTag(stdout);
+  }
+  printf(": aNotSafeToBreak=%s frame=", aNotSafeToBreak ? "true" : "false");
+  pfd->mFrame->ListTag(stdout);
+  printf(" frameWidth=%d, margins=%d,%d\n",
+         pfd->mBounds.IEnd(lineWM) + endMargin - psd->mICoord, startMargin,
+         endMargin);
+#endif
+
+  // Set outside to true if the result of the reflow leads to the
+  // frame sticking outside of our available area.
+  bool outside =
+      pfd->mBounds.IEnd(lineWM) - mTrimmableISize + endMargin > psd->mIEnd;
+  if (!outside) {
+    // If it fits, it fits
+#ifdef NOISY_CAN_PLACE_FRAME
+    printf("   ==> inside\n");
+#endif
+    return true;
+  }
+  *aOptionalBreakAfterFits = false;
+
+  // When it doesn't fit, check for a few special conditions where we
+  // allow it to fit anyway.
+  if (0 == startMargin + pfd->mBounds.ISize(lineWM) + endMargin) {
+    // Empty frames always fit right where they are
+#ifdef NOISY_CAN_PLACE_FRAME
+    printf("   ==> empty frame fits\n");
+#endif
+    return true;
+  }
+
+  // another special case:  always place a BR
+  if (pfd->mFrame->IsBrFrame()) {
+#ifdef NOISY_CAN_PLACE_FRAME
+    printf("   ==> BR frame fits\n");
+#endif
+    return true;
+  }
+
+  if (aNotSafeToBreak) {
+    // There are no frames on the line that take up width and the line is
+    // not impacted by floats, so we must allow the current frame to be
+    // placed on the line
+#ifdef NOISY_CAN_PLACE_FRAME
+    printf("   ==> not-safe and not-impacted fits: ");
+    while (nullptr != psd) {
+      printf("<psd=%p x=%d left=%d> ", psd, psd->mICoord, psd->mIStart);
+      psd = psd->mParent;
+    }
+    printf("\n");
+#endif
+    return true;
+  }
+
+  // Special check for span frames
+  if (pfd->mSpan && pfd->mSpan->mContainsFloat) {
+    // If the span either directly or indirectly contains a float then
+    // it fits. Why? It's kind of complicated, but here goes:
+    //
+    // 1. CanPlaceFrame is used for all frame placements on a line,
+    // and in a span. This includes recursively placement of frames
+    // inside of spans, and the span itself. Because the logic always
+    // checks for room before proceeding (the code above here), the
+    // only things on a line will be those things that "fit".
+    //
+    // 2. Before a float is placed on a line, the line has to be empty
+    // (otherwise it's a "below current line" float and will be placed
+    // after the line).
+    //
+    // Therefore, if the span directly or indirectly has a float
+    // then it means that at the time of the placement of the float
+    // the line was empty. Because of #1, only the frames that fit can
+    // be added after that point, therefore we can assume that the
+    // current span being placed has fit.
+    //
+    // So how do we get here and have a span that should already fit
+    // and yet doesn't: Simple: span's that have the no-wrap attribute
+    // set on them and contain a float and are placed where they
+    // don't naturally fit.
+    return true;
+  }
+
+  if (aFrameCanContinueTextRun) {
+    // Let it fit, but we reserve the right to roll back.
+    // Note that we usually won't get here because a text frame will break
+    // itself to avoid exceeding the available width.
+    // We'll only get here for text frames that couldn't break early enough.
+#ifdef NOISY_CAN_PLACE_FRAME
+    printf("   ==> placing overflowing textrun, requesting backup\n");
+#endif
+
+    // We will want to try backup.
+    mNeedBackup = true;
+    return true;
+  }
+
+#ifdef NOISY_CAN_PLACE_FRAME
+  printf("   ==> didn't fit\n");
+#endif
+  aStatus.SetInlineLineBreakBeforeAndReset();
+  return false;
+}
+
+/**
+ * Place the frame. Update running counters.
+ */
+void nsLineLayout::PlaceFrame(PerFrameData* pfd, ReflowOutput& aMetrics) {
+  WritingMode lineWM = mRootSpan->mWritingMode;
+
+  // If the frame's block direction does not match the line's, we can't use
+  // its ascent; instead, treat it as a block with baseline at the block-end
+  // edge (or block-begin in the case of an "inverted" line).
+  if (pfd->mWritingMode.GetBlockDir() != lineWM.GetBlockDir()) {
+    pfd->mAscent = lineWM.IsAlphabeticalBaseline()
+                       ? lineWM.IsLineInverted() ? 0 : aMetrics.BSize(lineWM)
+                       : aMetrics.BSize(lineWM) / 2;
+  } else {
+    // For inline reflow participants, baseline may get assigned as the frame is
+    // vertically aligned, which happens after this.
+    const auto baselineSource = pfd->mFrame->StyleDisplay()->mBaselineSource;
+    if (baselineSource == StyleBaselineSource::Auto ||
+        pfd->mFrame->IsFrameOfType(nsIFrame::eLineParticipant)) {
+      if (aMetrics.BlockStartAscent() == ReflowOutput::ASK_FOR_BASELINE) {
+        pfd->mAscent = pfd->mFrame->GetLogicalBaseline(lineWM);
+      } else {
+        pfd->mAscent = aMetrics.BlockStartAscent();
+      }
+    } else {
+      const auto sourceGroup = [baselineSource]() {
+        switch (baselineSource) {
+          case StyleBaselineSource::First:
+            return BaselineSharingGroup::First;
+          case StyleBaselineSource::Last:
+            return BaselineSharingGroup::Last;
+          case StyleBaselineSource::Auto:
+            break;
+        }
+        MOZ_ASSERT_UNREACHABLE("Auto should be already handled?");
+        return BaselineSharingGroup::First;
+      }();
+      // We ignore line-layout specific layout quirks by setting
+      // `BaselineExportContext::Other`.
+      // Note(dshin): For a lot of frames, the export context does not make a
+      // difference, and we may be wasting the value cached in
+      // `BlockStartAscent`.
+      pfd->mAscent = pfd->mFrame->GetLogicalBaseline(
+          lineWM, sourceGroup, BaselineExportContext::Other);
+    }
+  }
+
+  // Advance to next inline coordinate
+  mCurrentSpan->mICoord = pfd->mBounds.IEnd(lineWM) + pfd->mMargin.IEnd(lineWM);
+
+  // Count the number of non-placeholder frames on the line...
+  if (pfd->mFrame->IsPlaceholderFrame()) {
+    NS_ASSERTION(
+        pfd->mBounds.ISize(lineWM) == 0 && pfd->mBounds.BSize(lineWM) == 0,
+        "placeholders should have 0 width/height (checking "
+        "placeholders were never counted by the old code in "
+        "this function)");
+  } else {
+    mTotalPlacedFrames++;
+  }
+}
+
+void nsLineLayout::AddMarkerFrame(nsIFrame* aFrame,
+                                  const ReflowOutput& aMetrics) {
+  NS_ASSERTION(mCurrentSpan == mRootSpan, "bad linelayout user");
+  NS_ASSERTION(mGotLineBox, "must have line box");
+
+  nsBlockFrame* blockFrame = do_QueryFrame(LineContainerFrame());
+  MOZ_ASSERT(blockFrame, "must be for block");
+  if (!blockFrame->MarkerIsEmpty()) {
+    mHasMarker = true;
+    mLineBox->SetHasMarker();
+  }
+
+  WritingMode lineWM = mRootSpan->mWritingMode;
+  PerFrameData* pfd = NewPerFrameData(aFrame);
+  PerSpanData* psd = mRootSpan;
+
+  MOZ_ASSERT(psd->mFirstFrame, "adding marker to an empty line?");
+  // Prepend the marker frame to the line.
+  psd->mFirstFrame->mPrev = pfd;
+  pfd->mNext = psd->mFirstFrame;
+  psd->mFirstFrame = pfd;
+
+  pfd->mIsMarker = true;
+  if (aMetrics.BlockStartAscent() == ReflowOutput::ASK_FOR_BASELINE) {
+    pfd->mAscent = aFrame->GetLogicalBaseline(lineWM);
+  } else {
+    pfd->mAscent = aMetrics.BlockStartAscent();
+  }
+
+  // Note: block-coord value will be updated during block-direction alignment
+  pfd->mBounds = LogicalRect(lineWM, aFrame->GetRect(), ContainerSize());
+  pfd->mOverflowAreas = aMetrics.mOverflowAreas;
+}
+
+void nsLineLayout::RemoveMarkerFrame(nsIFrame* aFrame) {
+  PerSpanData* psd = mCurrentSpan;
+  MOZ_ASSERT(psd == mRootSpan, "::marker on non-root span?");
+  MOZ_ASSERT(psd->mFirstFrame->mFrame == aFrame,
+             "::marker is not the first frame?");
+  PerFrameData* pfd = psd->mFirstFrame;
+  MOZ_ASSERT(pfd != psd->mLastFrame, "::marker is the only frame?");
+  pfd->mNext->mPrev = nullptr;
+  psd->mFirstFrame = pfd->mNext;
+  FreeFrame(pfd);
+}
+#ifdef DEBUG
+void nsLineLayout::DumpPerSpanData(PerSpanData* psd, int32_t aIndent) {
+  nsIFrame::IndentBy(stdout, aIndent);
+  printf("%p: left=%d x=%d right=%d\n", static_cast<void*>(psd), psd->mIStart,
+         psd->mICoord, psd->mIEnd);
+  PerFrameData* pfd = psd->mFirstFrame;
+  while (nullptr != pfd) {
+    nsIFrame::IndentBy(stdout, aIndent + 1);
+    pfd->mFrame->ListTag(stdout);
+    nsRect rect =
+        pfd->mBounds.GetPhysicalRect(psd->mWritingMode, ContainerSize());
+    printf(" %d,%d,%d,%d\n", rect.x, rect.y, rect.width, rect.height);
+    if (pfd->mSpan) {
+      DumpPerSpanData(pfd->mSpan, aIndent + 1);
+    }
+    pfd = pfd->mNext;
+  }
+}
+#endif
+
+void nsLineLayout::RecordNoWrapFloat(nsIFrame* aFloat) {
+  GetOutermostLineLayout()->mBlockRS->mNoWrapFloats.AppendElement(aFloat);
+}
+
+void nsLineLayout::FlushNoWrapFloats() {
+  auto& noWrapFloats = GetOutermostLineLayout()->mBlockRS->mNoWrapFloats;
+  for (nsIFrame* floatedFrame : noWrapFloats) {
+    TryToPlaceFloat(floatedFrame);
+  }
+  noWrapFloats.Clear();
+}
+
+bool nsLineLayout::TryToPlaceFloat(nsIFrame* aFloat) {
+  // Add mTrimmableISize to the available width since if the line ends here, the
+  // width of the inline content will be reduced by mTrimmableISize.
+  nscoord availableISize =
+      mCurrentSpan->mIEnd - (mCurrentSpan->mICoord - mTrimmableISize);
+  NS_ASSERTION(!(aFloat->IsLetterFrame() && GetFirstLetterStyleOK()),
+               "FirstLetterStyle set on line with floating first letter");
+  return GetOutermostLineLayout()->AddFloat(aFloat, availableISize);
+}
+
+bool nsLineLayout::NotifyOptionalBreakPosition(nsIFrame* aFrame,
+                                               int32_t aOffset, bool aFits,
+                                               gfxBreakPriority aPriority) {
+  NS_ASSERTION(!aFits || !mNeedBackup,
+               "Shouldn't be updating the break position with a break that fits"
+               " after we've already flagged an overrun");
+  MOZ_ASSERT(mCurrentSpan, "Should be doing line layout");
+  if (mCurrentSpan->mNoWrap) {
+    FlushNoWrapFloats();
+  }
+
+  // Remember the last break position that fits; if there was no break that fit,
+  // just remember the first break
+  if ((aFits && aPriority >= mLastOptionalBreakPriority) ||
+      !mLastOptionalBreakFrame) {
+    mLastOptionalBreakFrame = aFrame;
+    mLastOptionalBreakFrameOffset = aOffset;
+    mLastOptionalBreakPriority = aPriority;
+  }
+  return aFrame && mForceBreakFrame == aFrame &&
+         mForceBreakFrameOffset == aOffset;
+}
+
+#define VALIGN_OTHER 0
+#define VALIGN_TOP 1
+#define VALIGN_BOTTOM 2
+
+void nsLineLayout::VerticalAlignLine() {
+  // Partially place the children of the block frame. The baseline for
+  // this operation is set to zero so that the y coordinates for all
+  // of the placed children will be relative to there.
+  PerSpanData* psd = mRootSpan;
+  VerticalAlignFrames(psd);
+
+  // *** Note that comments here still use the anachronistic term
+  // "line-height" when we really mean "size of the line in the block
+  // direction", "vertical-align" when we really mean "alignment in
+  // the block direction", and "top" and "bottom" when we really mean
+  // "block start" and "block end". This is partly for brevity and
+  // partly to retain the association with the CSS line-height and
+  // vertical-align properties.
+  //
+  // Compute the line-height. The line-height will be the larger of:
+  //
+  // [1] maxBCoord - minBCoord (the distance between the first child's
+  // block-start edge and the last child's block-end edge)
+  //
+  // [2] the maximum logical box block size (since not every frame may have
+  // participated in #1; for example: "top" and "botttom" aligned frames)
+  //
+  // [3] the minimum line height ("line-height" property set on the
+  // block frame)
+  nscoord lineBSize = psd->mMaxBCoord - psd->mMinBCoord;
+
+  // Now that the line-height is computed, we need to know where the
+  // baseline is in the line. Position baseline so that mMinBCoord is just
+  // inside the start of the line box.
+  nscoord baselineBCoord;
+  if (psd->mMinBCoord < 0) {
+    baselineBCoord = mBStartEdge - psd->mMinBCoord;
+  } else {
+    baselineBCoord = mBStartEdge;
+  }
+
+  // It's also possible that the line block-size isn't tall enough because
+  // of "top" and "bottom" aligned elements that were not accounted for in
+  // min/max BCoord.
+  //
+  // The CSS2 spec doesn't really say what happens when to the
+  // baseline in this situations. What we do is if the largest start
+  // aligned box block size is greater than the line block-size then we leave
+  // the baseline alone. If the largest end aligned box is greater
+  // than the line block-size then we slide the baseline forward by the extra
+  // amount.
+  //
+  // Navigator 4 gives precedence to the first top/bottom aligned
+  // object.  We just let block end aligned objects win.
+  if (lineBSize < mMaxEndBoxBSize) {
+    // When the line is shorter than the maximum block start aligned box
+    nscoord extra = mMaxEndBoxBSize - lineBSize;
+    baselineBCoord += extra;
+    lineBSize = mMaxEndBoxBSize;
+  }
+  if (lineBSize < mMaxStartBoxBSize) {
+    lineBSize = mMaxStartBoxBSize;
+  }
+#ifdef NOISY_BLOCKDIR_ALIGN
+  printf("  [line]==> lineBSize=%d baselineBCoord=%d\n", lineBSize,
+         baselineBCoord);
+#endif
+
+  // Now position all of the frames in the root span. We will also
+  // recurse over the child spans and place any frames we find with
+  // vertical-align: top or bottom.
+  // XXX PERFORMANCE: set a bit per-span to avoid the extra work
+  // (propagate it upward too)
+  WritingMode lineWM = psd->mWritingMode;
+  for (PerFrameData* pfd = psd->mFirstFrame; pfd; pfd = pfd->mNext) {
+    if (pfd->mBlockDirAlign == VALIGN_OTHER) {
+      pfd->mBounds.BStart(lineWM) += baselineBCoord;
+      pfd->mFrame->SetRect(lineWM, pfd->mBounds, ContainerSize());
+    }
+  }
+  PlaceTopBottomFrames(psd, -mBStartEdge, lineBSize);
+
+  mFinalLineBSize = lineBSize;
+  if (mGotLineBox) {
+    // Fill in returned line-box and max-element-width data
+    mLineBox->SetBounds(lineWM, psd->mIStart, mBStartEdge,
+                        psd->mICoord - psd->mIStart, lineBSize,
+                        ContainerSize());
+
+    mLineBox->SetLogicalAscent(baselineBCoord - mBStartEdge);
+#ifdef NOISY_BLOCKDIR_ALIGN
+    printf("  [line]==> bounds{x,y,w,h}={%d,%d,%d,%d} lh=%d a=%d\n",
+           mLineBox->GetBounds().IStart(lineWM),
+           mLineBox->GetBounds().BStart(lineWM),
+           mLineBox->GetBounds().ISize(lineWM),
+           mLineBox->GetBounds().BSize(lineWM), mFinalLineBSize,
+           mLineBox->GetLogicalAscent());
+#endif
+  }
+}
+
+// Place frames with CSS property vertical-align: top or bottom.
+void nsLineLayout::PlaceTopBottomFrames(PerSpanData* psd,
+                                        nscoord aDistanceFromStart,
+                                        nscoord aLineBSize) {
+  for (PerFrameData* pfd = psd->mFirstFrame; pfd; pfd = pfd->mNext) {
+    PerSpanData* span = pfd->mSpan;
+#ifdef DEBUG
+    NS_ASSERTION(0xFF != pfd->mBlockDirAlign, "umr");
+#endif
+    WritingMode lineWM = mRootSpan->mWritingMode;
+    nsSize containerSize = ContainerSizeForSpan(psd);
+    switch (pfd->mBlockDirAlign) {
+      case VALIGN_TOP:
+        if (span) {
+          pfd->mBounds.BStart(lineWM) = -aDistanceFromStart - span->mMinBCoord;
+        } else {
+          pfd->mBounds.BStart(lineWM) =
+              -aDistanceFromStart + pfd->mMargin.BStart(lineWM);
+        }
+        pfd->mFrame->SetRect(lineWM, pfd->mBounds, containerSize);
+#ifdef NOISY_BLOCKDIR_ALIGN
+        printf("    ");
+        pfd->mFrame->ListTag(stdout);
+        printf(": y=%d dTop=%d [bp.top=%d topLeading=%d]\n",
+               pfd->mBounds.BStart(lineWM), aDistanceFromStart,
+               span ? pfd->mBorderPadding.BStart(lineWM) : 0,
+               span ? span->mBStartLeading : 0);
+#endif
+        break;
+      case VALIGN_BOTTOM:
+        if (span) {
+          // Compute bottom leading
+          pfd->mBounds.BStart(lineWM) =
+              -aDistanceFromStart + aLineBSize - span->mMaxBCoord;
+        } else {
+          pfd->mBounds.BStart(lineWM) = -aDistanceFromStart + aLineBSize -
+                                        pfd->mMargin.BEnd(lineWM) -
+                                        pfd->mBounds.BSize(lineWM);
+        }
+        pfd->mFrame->SetRect(lineWM, pfd->mBounds, containerSize);
+#ifdef NOISY_BLOCKDIR_ALIGN
+        printf("    ");
+        pfd->mFrame->ListTag(stdout);
+        printf(": y=%d\n", pfd->mBounds.BStart(lineWM));
+#endif
+        break;
+    }
+    if (span) {
+      nscoord fromStart = aDistanceFromStart + pfd->mBounds.BStart(lineWM);
+      PlaceTopBottomFrames(span, fromStart, aLineBSize);
+    }
+  }
+}
+
+static nscoord GetBSizeOfEmphasisMarks(nsIFrame* aSpanFrame, float aInflation) {
+  RefPtr<nsFontMetrics> fm = nsLayoutUtils::GetFontMetricsOfEmphasisMarks(
+      aSpanFrame->Style(), aSpanFrame->PresContext(), aInflation);
+  return fm->MaxHeight();
+}
+
+void nsLineLayout::AdjustLeadings(nsIFrame* spanFrame, PerSpanData* psd,
+                                  const nsStyleText* aStyleText,
+                                  float aInflation,
+                                  bool* aZeroEffectiveSpanBox) {
+  MOZ_ASSERT(spanFrame == psd->mFrame->mFrame);
+  nscoord requiredStartLeading = 0;
+  nscoord requiredEndLeading = 0;
+  if (spanFrame->IsRubyFrame()) {
+    // We may need to extend leadings here for ruby annotations as
+    // required by section Line Spacing in the CSS Ruby spec.
+    // See http://dev.w3.org/csswg/css-ruby/#line-height
+    auto rubyFrame = static_cast<nsRubyFrame*>(spanFrame);
+    RubyBlockLeadings leadings = rubyFrame->GetBlockLeadings();
+    requiredStartLeading += leadings.mStart;
+    requiredEndLeading += leadings.mEnd;
+  }
+  if (aStyleText->HasEffectiveTextEmphasis()) {
+    nscoord bsize = GetBSizeOfEmphasisMarks(spanFrame, aInflation);
+    LogicalSide side = aStyleText->TextEmphasisSide(mRootSpan->mWritingMode);
+    if (side == eLogicalSideBStart) {
+      requiredStartLeading += bsize;
+    } else {
+      MOZ_ASSERT(side == eLogicalSideBEnd,
+                 "emphasis marks must be in block axis");
+      requiredEndLeading += bsize;
+    }
+  }
+
+  nscoord requiredLeading = requiredStartLeading + requiredEndLeading;
+  // If we do not require any additional leadings, don't touch anything
+  // here even if it is greater than the original leading, because the
+  // latter could be negative.
+  if (requiredLeading != 0) {
+    nscoord leading = psd->mBStartLeading + psd->mBEndLeading;
+    nscoord deltaLeading = requiredLeading - leading;
+    if (deltaLeading > 0) {
+      // If the total leading is not wide enough for ruby annotations
+      // and/or emphasis marks, extend the side which is not enough. If
+      // both sides are not wide enough, replace the leadings with the
+      // requested values.
+      if (requiredStartLeading < psd->mBStartLeading) {
+        psd->mBEndLeading += deltaLeading;
+      } else if (requiredEndLeading < psd->mBEndLeading) {
+        psd->mBStartLeading += deltaLeading;
+      } else {
+        psd->mBStartLeading = requiredStartLeading;
+        psd->mBEndLeading = requiredEndLeading;
+      }
+      psd->mLogicalBSize += deltaLeading;
+      // We have adjusted the leadings, it is no longer a zero
+      // effective span box.
+      *aZeroEffectiveSpanBox = false;
+    }
+  }
+}
+
+static float GetInflationForBlockDirAlignment(nsIFrame* aFrame,
+                                              nscoord aInflationMinFontSize) {
+  if (aFrame->IsInSVGTextSubtree()) {
+    const nsIFrame* container =
+        nsLayoutUtils::GetClosestFrameOfType(aFrame, LayoutFrameType::SVGText);
+    NS_ASSERTION(container, "expected to find an ancestor SVGTextFrame");
+    return static_cast<const SVGTextFrame*>(container)
+        ->GetFontSizeScaleFactor();
+  }
+  return nsLayoutUtils::FontSizeInflationInner(aFrame, aInflationMinFontSize);
+}
+
+#define BLOCKDIR_ALIGN_FRAMES_NO_MINIMUM nscoord_MAX
+#define BLOCKDIR_ALIGN_FRAMES_NO_MAXIMUM nscoord_MIN
+
+// Place frames in the block direction within a given span (CSS property
+// vertical-align) Note: this doesn't place frames with vertical-align:
+// top or bottom as those have to wait until the entire line box block
+// size is known. This is called after the span frame has finished being
+// reflowed so that we know its block size.
+void nsLineLayout::VerticalAlignFrames(PerSpanData* psd) {
+  // Get parent frame info
+  PerFrameData* spanFramePFD = psd->mFrame;
+  nsIFrame* spanFrame = spanFramePFD->mFrame;
+
+  // Get the parent frame's font for all of the frames in this span
+  float inflation =
+      GetInflationForBlockDirAlignment(spanFrame, mInflationMinFontSize);
+  RefPtr<nsFontMetrics> fm =
+      nsLayoutUtils::GetFontMetricsForFrame(spanFrame, inflation);
+
+  bool preMode = mStyleText->WhiteSpaceIsSignificant();
+
+  // See if the span is an empty continuation. It's an empty continuation iff:
+  // - it has a prev-in-flow
+  // - it has no next in flow
+  // - it's zero sized
+  WritingMode lineWM = mRootSpan->mWritingMode;
+  bool emptyContinuation = psd != mRootSpan && spanFrame->GetPrevInFlow() &&
+                           !spanFrame->GetNextInFlow() &&
+                           spanFramePFD->mBounds.IsZeroSize();
+
+#ifdef NOISY_BLOCKDIR_ALIGN
+  printf("[%sSpan]", (psd == mRootSpan) ? "Root" : "");
+  spanFrame->ListTag(stdout);
+  printf(": preMode=%s strictMode=%s w/h=%d,%d emptyContinuation=%s",
+         preMode ? "yes" : "no",
+         mPresContext->CompatibilityMode() != eCompatibility_NavQuirks ? "yes"
+                                                                       : "no",
+         spanFramePFD->mBounds.ISize(lineWM),
+         spanFramePFD->mBounds.BSize(lineWM), emptyContinuation ? "yes" : "no");
+  if (psd != mRootSpan) {
+    printf(" bp=%d,%d,%d,%d margin=%d,%d,%d,%d",
+           spanFramePFD->mBorderPadding.Top(lineWM),
+           spanFramePFD->mBorderPadding.Right(lineWM),
+           spanFramePFD->mBorderPadding.Bottom(lineWM),
+           spanFramePFD->mBorderPadding.Left(lineWM),
+           spanFramePFD->mMargin.Top(lineWM),
+           spanFramePFD->mMargin.Right(lineWM),
+           spanFramePFD->mMargin.Bottom(lineWM),
+           spanFramePFD->mMargin.Left(lineWM));
+  }
+  printf("\n");
+#endif
+
+  // Compute the span's zeroEffectiveSpanBox flag. What we are trying
+  // to determine is how we should treat the span: should it act
+  // "normally" according to css2 or should it effectively
+  // "disappear".
+  //
+  // In general, if the document being processed is in full standards
+  // mode then it should act normally (with one exception). The
+  // exception case is when a span is continued and yet the span is
+  // empty (e.g. compressed whitespace). For this kind of span we treat
+  // it as if it were not there so that it doesn't impact the
+  // line block-size.
+  //
+  // In almost standards mode or quirks mode, we should sometimes make
+  // it disappear. The cases that matter are those where the span
+  // contains no real text elements that would provide an ascent and
+  // descent and height. However, if css style elements have been
+  // applied to the span (border/padding/margin) so that it's clear the
+  // document author is intending css2 behavior then we act as if strict
+  // mode is set.
+  //
+  // This code works correctly for preMode, because a blank line
+  // in PRE mode is encoded as a text node with a LF in it, since
+  // text nodes with only whitespace are considered in preMode.
+  //
+  // Much of this logic is shared with the various implementations of
+  // nsIFrame::IsEmpty since they need to duplicate the way it makes
+  // some lines empty.  However, nsIFrame::IsEmpty can't be reused here
+  // since this code sets zeroEffectiveSpanBox even when there are
+  // non-empty children.
+  bool zeroEffectiveSpanBox = false;
+  // XXXldb If we really have empty continuations, then all these other
+  // checks don't make sense for them.
+  // XXXldb This should probably just use nsIFrame::IsSelfEmpty, assuming that
+  // it agrees with this code.  (If it doesn't agree, it probably should.)
+  if ((emptyContinuation ||
+       mPresContext->CompatibilityMode() != eCompatibility_FullStandards) &&
+      ((psd == mRootSpan) || (spanFramePFD->mBorderPadding.IsAllZero() &&
+                              spanFramePFD->mMargin.IsAllZero()))) {
+    // This code handles an issue with compatibility with non-css
+    // conformant browsers. In particular, there are some cases
+    // where the font-size and line-height for a span must be
+    // ignored and instead the span must *act* as if it were zero
+    // sized. In general, if the span contains any non-compressed
+    // text then we don't use this logic.
+    // However, this is not propagated outwards, since (in compatibility
+    // mode) we don't want big line heights for things like
+    // <p><font size="-1">Text</font></p>
+
+    // We shouldn't include any whitespace that collapses, unless we're
+    // preformatted (in which case it shouldn't, but the width=0 test is
+    // perhaps incorrect).  This includes whitespace at the beginning of
+    // a line and whitespace preceded (?) by other whitespace.
+    // See bug 134580 and bug 155333.
+    zeroEffectiveSpanBox = true;
+    for (PerFrameData* pfd = psd->mFirstFrame; pfd; pfd = pfd->mNext) {
+      if (pfd->mIsTextFrame &&
+          (pfd->mIsNonWhitespaceTextFrame || preMode ||
+           pfd->mBounds.ISize(mRootSpan->mWritingMode) != 0)) {
+        zeroEffectiveSpanBox = false;
+        break;
+      }
+    }
+  }
+
+  // Setup baselineBCoord, minBCoord, and maxBCoord
+  nscoord baselineBCoord, minBCoord, maxBCoord;
+  if (psd == mRootSpan) {
+    // Use a zero baselineBCoord since we don't yet know where the baseline
+    // will be (until we know how tall the line is; then we will
+    // know). In addition, use extreme values for the minBCoord and maxBCoord
+    // values so that only the child frames will impact their values
+    // (since these are children of the block, there is no span box to
+    // provide initial values).
+    baselineBCoord = 0;
+    minBCoord = BLOCKDIR_ALIGN_FRAMES_NO_MINIMUM;
+    maxBCoord = BLOCKDIR_ALIGN_FRAMES_NO_MAXIMUM;
+#ifdef NOISY_BLOCKDIR_ALIGN
+    printf("[RootSpan]");
+    spanFrame->ListTag(stdout);
+    printf(
+        ": pass1 valign frames: topEdge=%d minLineBSize=%d "
+        "zeroEffectiveSpanBox=%s\n",
+        mBStartEdge, mMinLineBSize, zeroEffectiveSpanBox ? "yes" : "no");
+#endif
+  } else {
+    // Compute the logical block size for this span. The logical block size
+    // is based on the "line-height" value, not the font-size. Also
+    // compute the top leading.
+    float inflation =
+        GetInflationForBlockDirAlignment(spanFrame, mInflationMinFontSize);
+    nscoord logicalBSize = ReflowInput::CalcLineHeight(
+        *spanFrame->Style(), spanFrame->PresContext(), spanFrame->GetContent(),
+        mLineContainerRI.ComputedHeight(), inflation);
+    nscoord contentBSize = spanFramePFD->mBounds.BSize(lineWM) -
+                           spanFramePFD->mBorderPadding.BStartEnd(lineWM);
+
+    // Special-case for a ::first-letter frame, set the line height to
+    // the frame block size if the user has left line-height == normal
+    const nsStyleText* styleText = spanFrame->StyleText();
+    if (spanFramePFD->mIsLetterFrame && !spanFrame->GetPrevInFlow() &&
+        styleText->mLineHeight.IsNormal()) {
+      logicalBSize = spanFramePFD->mBounds.BSize(lineWM);
+    }
+
+    nscoord leading = logicalBSize - contentBSize;
+    psd->mBStartLeading = leading / 2;
+    psd->mBEndLeading = leading - psd->mBStartLeading;
+    psd->mLogicalBSize = logicalBSize;
+    AdjustLeadings(spanFrame, psd, styleText, inflation, &zeroEffectiveSpanBox);
+
+    if (zeroEffectiveSpanBox) {
+      // When the span-box is to be ignored, zero out the initial
+      // values so that the span doesn't impact the final line
+      // height. The contents of the span can impact the final line
+      // height.
+
+      // Note that things are readjusted for this span after its children
+      // are reflowed
+      minBCoord = BLOCKDIR_ALIGN_FRAMES_NO_MINIMUM;
+      maxBCoord = BLOCKDIR_ALIGN_FRAMES_NO_MAXIMUM;
+    } else {
+      // The initial values for the min and max block coord values are in the
+      // span's coordinate space, and cover the logical block size of the span.
+      // If there are child frames in this span that stick out of this area
+      // then the minBCoord and maxBCoord are updated by the amount of logical
+      // blockSize that is outside this range.
+      minBCoord =
+          spanFramePFD->mBorderPadding.BStart(lineWM) - psd->mBStartLeading;
+      maxBCoord = minBCoord + psd->mLogicalBSize;
+    }
+
+    // This is the distance from the top edge of the parents visual
+    // box to the baseline. The span already computed this for us,
+    // so just use it.
+    *psd->mBaseline = baselineBCoord = spanFramePFD->mAscent;
+
+#ifdef NOISY_BLOCKDIR_ALIGN
+    printf("[%sSpan]", (psd == mRootSpan) ? "Root" : "");
+    spanFrame->ListTag(stdout);
+    printf(
+        ": baseLine=%d logicalBSize=%d topLeading=%d h=%d bp=%d,%d "
+        "zeroEffectiveSpanBox=%s\n",
+        baselineBCoord, psd->mLogicalBSize, psd->mBStartLeading,
+        spanFramePFD->mBounds.BSize(lineWM),
+        spanFramePFD->mBorderPadding.Top(lineWM),
+        spanFramePFD->mBorderPadding.Bottom(lineWM),
+        zeroEffectiveSpanBox ? "yes" : "no");
+#endif
+  }
+
+  nscoord maxStartBoxBSize = 0;
+  nscoord maxEndBoxBSize = 0;
+  PerFrameData* pfd = psd->mFirstFrame;
+  while (nullptr != pfd) {
+    nsIFrame* frame = pfd->mFrame;
+
+    // sanity check (see bug 105168, non-reproducible crashes from null frame)
+    NS_ASSERTION(frame,
+                 "null frame in PerFrameData - something is very very bad");
+    if (!frame) {
+      return;
+    }
+
+    // Compute the logical block size of the frame
+    nscoord logicalBSize;
+    PerSpanData* frameSpan = pfd->mSpan;
+    if (frameSpan) {
+      // For span frames the logical-block-size and start-leading were
+      // pre-computed when the span was reflowed.
+      logicalBSize = frameSpan->mLogicalBSize;
+    } else {
+      // For other elements the logical block size is the same as the
+      // frame's block size plus its margins.
+      logicalBSize =
+          pfd->mBounds.BSize(lineWM) + pfd->mMargin.BStartEnd(lineWM);
+      if (logicalBSize < 0 &&
+          mPresContext->CompatibilityMode() != eCompatibility_FullStandards) {
+        pfd->mAscent -= logicalBSize;
+        logicalBSize = 0;
+      }
+    }
+
+    // Get vertical-align property ("vertical-align" is the CSS name for
+    // block-direction align)
+    const auto& verticalAlign = frame->StyleDisplay()->mVerticalAlign;
+    Maybe<StyleVerticalAlignKeyword> verticalAlignEnum =
+        frame->VerticalAlignEnum();
+#ifdef NOISY_BLOCKDIR_ALIGN
+    printf("  [frame]");
+    frame->ListTag(stdout);
+    printf(": verticalAlignIsKw=%d (enum == %d", verticalAlign.IsKeyword(),
+           verticalAlign.IsKeyword()
+               ? static_cast<int>(verticalAlign.AsKeyword())
+               : -1);
+    if (verticalAlignEnum) {
+      printf(", after SVG dominant-baseline conversion == %d",
+             static_cast<int>(*verticalAlignEnum));
+    }
+    printf(")\n");
+#endif
+
+    if (verticalAlignEnum) {
+      StyleVerticalAlignKeyword keyword = *verticalAlignEnum;
+      if (lineWM.IsVertical()) {
+        if (keyword == StyleVerticalAlignKeyword::Middle) {
+          // For vertical writing mode where the dominant baseline is centered
+          // (i.e. text-orientation is not sideways-*), we remap 'middle' to
+          // 'middle-with-baseline' so that images align sensibly with the
+          // center-baseline-aligned text.
+          if (!lineWM.IsSideways()) {
+            keyword = StyleVerticalAlignKeyword::MozMiddleWithBaseline;
+          }
+        } else if (lineWM.IsLineInverted()) {
+          // Swap the meanings of top and bottom when line is inverted
+          // relative to block direction.
+          switch (keyword) {
+            case StyleVerticalAlignKeyword::Top:
+              keyword = StyleVerticalAlignKeyword::Bottom;
+              break;
+            case StyleVerticalAlignKeyword::Bottom:
+              keyword = StyleVerticalAlignKeyword::Top;
+              break;
+            case StyleVerticalAlignKeyword::TextTop:
+              keyword = StyleVerticalAlignKeyword::TextBottom;
+              break;
+            case StyleVerticalAlignKeyword::TextBottom:
+              keyword = StyleVerticalAlignKeyword::TextTop;
+              break;
+            default:
+              break;
+          }
+        }
+      }
+
+      // baseline coord that may be adjusted for script offset
+      nscoord revisedBaselineBCoord = baselineBCoord;
+
+      // For superscript and subscript, raise or lower the baseline of the box
+      // to the proper offset of the parent's box, then proceed as for BASELINE
+      if (keyword == StyleVerticalAlignKeyword::Sub ||
+          keyword == StyleVerticalAlignKeyword::Super) {
+        revisedBaselineBCoord += lineWM.FlowRelativeToLineRelativeFactor() *
+                                 (keyword == StyleVerticalAlignKeyword::Sub
+                                      ? fm->SubscriptOffset()
+                                      : -fm->SuperscriptOffset());
+        keyword = StyleVerticalAlignKeyword::Baseline;
+      }
+
+      switch (keyword) {
+        default:
+        case StyleVerticalAlignKeyword::Baseline:
+          pfd->mBounds.BStart(lineWM) = revisedBaselineBCoord - pfd->mAscent;
+          pfd->mBlockDirAlign = VALIGN_OTHER;
+          break;
+
+        case StyleVerticalAlignKeyword::Top: {
+          pfd->mBlockDirAlign = VALIGN_TOP;
+          nscoord subtreeBSize = logicalBSize;
+          if (frameSpan) {
+            subtreeBSize = frameSpan->mMaxBCoord - frameSpan->mMinBCoord;
+            NS_ASSERTION(subtreeBSize >= logicalBSize,
+                         "unexpected subtree block size");
+          }
+          if (subtreeBSize > maxStartBoxBSize) {
+            maxStartBoxBSize = subtreeBSize;
+          }
+          break;
+        }
+
+        case StyleVerticalAlignKeyword::Bottom: {
+          pfd->mBlockDirAlign = VALIGN_BOTTOM;
+          nscoord subtreeBSize = logicalBSize;
+          if (frameSpan) {
+            subtreeBSize = frameSpan->mMaxBCoord - frameSpan->mMinBCoord;
+            NS_ASSERTION(subtreeBSize >= logicalBSize,
+                         "unexpected subtree block size");
+          }
+          if (subtreeBSize > maxEndBoxBSize) {
+            maxEndBoxBSize = subtreeBSize;
+          }
+          break;
+        }
+
+        case StyleVerticalAlignKeyword::Middle: {
+          // Align the midpoint of the frame with 1/2 the parents
+          // x-height above the baseline.
+          nscoord parentXHeight =
+              lineWM.FlowRelativeToLineRelativeFactor() * fm->XHeight();
+          if (frameSpan) {
+            pfd->mBounds.BStart(lineWM) =
+                baselineBCoord -
+                (parentXHeight + pfd->mBounds.BSize(lineWM)) / 2;
+          } else {
+            pfd->mBounds.BStart(lineWM) = baselineBCoord -
+                                          (parentXHeight + logicalBSize) / 2 +
+                                          pfd->mMargin.BStart(lineWM);
+          }
+          pfd->mBlockDirAlign = VALIGN_OTHER;
+          break;
+        }
+
+        case StyleVerticalAlignKeyword::TextTop: {
+          // The top of the logical box is aligned with the top of
+          // the parent element's text.
+          // XXX For vertical text we will need a new API to get the logical
+          //     max-ascent here
+          nscoord parentAscent =
+              lineWM.IsLineInverted() ? fm->MaxDescent() : fm->MaxAscent();
+          if (frameSpan) {
+            pfd->mBounds.BStart(lineWM) = baselineBCoord - parentAscent -
+                                          pfd->mBorderPadding.BStart(lineWM) +
+                                          frameSpan->mBStartLeading;
+          } else {
+            pfd->mBounds.BStart(lineWM) =
+                baselineBCoord - parentAscent + pfd->mMargin.BStart(lineWM);
+          }
+          pfd->mBlockDirAlign = VALIGN_OTHER;
+          break;
+        }
+
+        case StyleVerticalAlignKeyword::TextBottom: {
+          // The bottom of the logical box is aligned with the
+          // bottom of the parent elements text.
+          nscoord parentDescent =
+              lineWM.IsLineInverted() ? fm->MaxAscent() : fm->MaxDescent();
+          if (frameSpan) {
+            pfd->mBounds.BStart(lineWM) =
+                baselineBCoord + parentDescent - pfd->mBounds.BSize(lineWM) +
+                pfd->mBorderPadding.BEnd(lineWM) - frameSpan->mBEndLeading;
+          } else {
+            pfd->mBounds.BStart(lineWM) = baselineBCoord + parentDescent -
+                                          pfd->mBounds.BSize(lineWM) -
+                                          pfd->mMargin.BEnd(lineWM);
+          }
+          pfd->mBlockDirAlign = VALIGN_OTHER;
+          break;
+        }
+
+        case StyleVerticalAlignKeyword::MozMiddleWithBaseline: {
+          // Align the midpoint of the frame with the baseline of the parent.
+          if (frameSpan) {
+            pfd->mBounds.BStart(lineWM) =
+                baselineBCoord - pfd->mBounds.BSize(lineWM) / 2;
+          } else {
+            pfd->mBounds.BStart(lineWM) =
+                baselineBCoord - logicalBSize / 2 + pfd->mMargin.BStart(lineWM);
+          }
+          pfd->mBlockDirAlign = VALIGN_OTHER;
+          break;
+        }
+      }
+    } else {
+      // We have either a coord, a percent, or a calc().
+      nscoord offset = verticalAlign.AsLength().Resolve([&] {
+        // Percentages are like lengths, except treated as a percentage
+        // of the elements line block size value.
+        float inflation =
+            GetInflationForBlockDirAlignment(frame, mInflationMinFontSize);
+        return ReflowInput::CalcLineHeight(
+            *frame->Style(), frame->PresContext(), frame->GetContent(),
+            mLineContainerRI.ComputedBSize(), inflation);
+      });
+
+      // According to the CSS2 spec (10.8.1), a positive value
+      // "raises" the box by the given distance while a negative value
+      // "lowers" the box by the given distance (with zero being the
+      // baseline). Since Y coordinates increase towards the bottom of
+      // the screen we reverse the sign, unless the line orientation is
+      // inverted relative to block direction.
+      nscoord revisedBaselineBCoord =
+          baselineBCoord - offset * lineWM.FlowRelativeToLineRelativeFactor();
+      if (lineWM.IsCentralBaseline()) {
+        // If we're using a dominant center baseline, we align with the center
+        // of the frame being placed (bug 1133945).
+        pfd->mBounds.BStart(lineWM) =
+            revisedBaselineBCoord - pfd->mBounds.BSize(lineWM) / 2;
+      } else {
+        pfd->mBounds.BStart(lineWM) = revisedBaselineBCoord - pfd->mAscent;
+      }
+      pfd->mBlockDirAlign = VALIGN_OTHER;
+    }
+
+    // Update minBCoord/maxBCoord for frames that we just placed. Do not factor
+    // text into the equation.
+    if (pfd->mBlockDirAlign == VALIGN_OTHER) {
+      // Text frames do not contribute to the min/max Y values for the
+      // line (instead their parent frame's font-size contributes).
+      // XXXrbs -- relax this restriction because it causes text frames
+      //           to jam together when 'font-size-adjust' is enabled
+      //           and layout is using dynamic font heights (bug 20394)
+      //        -- Note #1: With this code enabled and with the fact that we are
+      //           not using Em[Ascent|Descent] as nsDimensions for text
+      //           metrics in GFX mean that the discussion in bug 13072 cannot
+      //           hold.
+      //        -- Note #2: We still don't want empty-text frames to interfere.
+      //           For example in quirks mode, avoiding empty text frames
+      //           prevents "tall" lines around elements like <hr> since the
+      //           rules of <hr> in quirks.css have pseudo text contents with LF
+      //           in them.
+      bool canUpdate;
+      if (pfd->mIsTextFrame) {
+        // Only consider text frames if they're not empty and
+        // line-height=normal.
+        canUpdate = pfd->mIsNonWhitespaceTextFrame &&
+                    frame->StyleText()->mLineHeight.IsNormal();
+      } else {
+        canUpdate = !pfd->mIsPlaceholder;
+      }
+
+      if (canUpdate) {
+        nscoord blockStart, blockEnd;
+        if (frameSpan) {
+          // For spans that were are now placing, use their position
+          // plus their already computed min-Y and max-Y values for
+          // computing blockStart and blockEnd.
+          blockStart = pfd->mBounds.BStart(lineWM) + frameSpan->mMinBCoord;
+          blockEnd = pfd->mBounds.BStart(lineWM) + frameSpan->mMaxBCoord;
+        } else {
+          blockStart =
+              pfd->mBounds.BStart(lineWM) - pfd->mMargin.BStart(lineWM);
+          blockEnd = blockStart + logicalBSize;
+        }
+        if (!preMode &&
+            mPresContext->CompatibilityMode() != eCompatibility_FullStandards &&
+            !logicalBSize) {
+          // Check if it's a BR frame that is not alone on its line (it
+          // is given a block size of zero to indicate this), and if so reset
+          // blockStart and blockEnd so that BR frames don't influence the line.
+          if (frame->IsBrFrame()) {
+            blockStart = BLOCKDIR_ALIGN_FRAMES_NO_MINIMUM;
+            blockEnd = BLOCKDIR_ALIGN_FRAMES_NO_MAXIMUM;
+          }
+        }
+        if (blockStart < minBCoord) minBCoord = blockStart;
+        if (blockEnd > maxBCoord) maxBCoord = blockEnd;
+#ifdef NOISY_BLOCKDIR_ALIGN
+        printf(
+            "     [frame]raw: a=%d h=%d bp=%d,%d logical: h=%d leading=%d y=%d "
+            "minBCoord=%d maxBCoord=%d\n",
+            pfd->mAscent, pfd->mBounds.BSize(lineWM),
+            pfd->mBorderPadding.Top(lineWM), pfd->mBorderPadding.Bottom(lineWM),
+            logicalBSize, frameSpan ? frameSpan->mBStartLeading : 0,
+            pfd->mBounds.BStart(lineWM), minBCoord, maxBCoord);
+#endif
+      }
+      if (psd != mRootSpan) {
+        frame->SetRect(lineWM, pfd->mBounds, ContainerSizeForSpan(psd));
+      }
+    }
+    pfd = pfd->mNext;
+  }
+
+  // Factor in the minimum line block-size when handling the root-span for
+  // the block.
+  if (psd == mRootSpan) {
+    // We should factor in the block element's minimum line-height (as
+    // defined in section 10.8.1 of the css2 spec) assuming that
+    // zeroEffectiveSpanBox is not set on the root span.  This only happens
+    // in some cases in quirks mode:
+    //  (1) if the root span contains non-whitespace text directly (this
+    //      is handled by zeroEffectiveSpanBox
+    //  (2) if this line has a ::marker
+    //  (3) if this is the last line of an LI, DT, or DD element
+    //      (The last line before a block also counts, but not before a
+    //      BR) (NN4/IE5 quirk)
+
+    // (1) and (2) above
+    bool applyMinLH = !zeroEffectiveSpanBox || mHasMarker;
+    bool isLastLine =
+        !mGotLineBox || (!mLineBox->IsLineWrapped() && !mLineEndsInBR);
+    if (!applyMinLH && isLastLine) {
+      nsIContent* blockContent = mRootSpan->mFrame->mFrame->GetContent();
+      if (blockContent) {
+        // (3) above, if the last line of LI, DT, or DD
+        if (blockContent->IsAnyOfHTMLElements(nsGkAtoms::li, nsGkAtoms::dt,
+                                              nsGkAtoms::dd)) {
+          applyMinLH = true;
+        }
+      }
+    }
+    if (applyMinLH) {
+      if (psd->mHasNonemptyContent || preMode || mHasMarker) {
+#ifdef NOISY_BLOCKDIR_ALIGN
+        printf("  [span]==> adjusting min/maxBCoord: currentValues: %d,%d",
+               minBCoord, maxBCoord);
+#endif
+        nscoord minimumLineBSize = mMinLineBSize;
+        nscoord blockStart = -nsLayoutUtils::GetCenteredFontBaseline(
+            fm, minimumLineBSize, lineWM.IsLineInverted());
+        nscoord blockEnd = blockStart + minimumLineBSize;
+
+        if (mStyleText->HasEffectiveTextEmphasis()) {
+          nscoord fontMaxHeight = fm->MaxHeight();
+          nscoord emphasisHeight =
+              GetBSizeOfEmphasisMarks(spanFrame, inflation);
+          nscoord delta = fontMaxHeight + emphasisHeight - minimumLineBSize;
+          if (delta > 0) {
+            if (minimumLineBSize < fontMaxHeight) {
+              // If the leadings are negative, fill them first.
+              nscoord ascent = fm->MaxAscent();
+              nscoord descent = fm->MaxDescent();
+              if (lineWM.IsLineInverted()) {
+                std::swap(ascent, descent);
+              }
+              blockStart = -ascent;
+              blockEnd = descent;
+              delta = emphasisHeight;
+            }
+            LogicalSide side = mStyleText->TextEmphasisSide(lineWM);
+            if (side == eLogicalSideBStart) {
+              blockStart -= delta;
+            } else {
+              blockEnd += delta;
+            }
+          }
+        }
+
+        if (blockStart < minBCoord) minBCoord = blockStart;
+        if (blockEnd > maxBCoord) maxBCoord = blockEnd;
+
+#ifdef NOISY_BLOCKDIR_ALIGN
+        printf(" new values: %d,%d\n", minBCoord, maxBCoord);
+#endif
+#ifdef NOISY_BLOCKDIR_ALIGN
+        printf(
+            "            Used mMinLineBSize: %d, blockStart: %d, blockEnd: "
+            "%d\n",
+            mMinLineBSize, blockStart, blockEnd);
+#endif
+      } else {
+        // XXX issues:
+        // [1] BR's on empty lines stop working
+        // [2] May not honor css2's notion of handling empty elements
+        // [3] blank lines in a pre-section ("\n") (handled with preMode)
+
+        // XXX Are there other problems with this?
+#ifdef NOISY_BLOCKDIR_ALIGN
+        printf(
+            "  [span]==> zapping min/maxBCoord: currentValues: %d,%d "
+            "newValues: 0,0\n",
+            minBCoord, maxBCoord);
+#endif
+        minBCoord = maxBCoord = 0;
+      }
+    }
+  }
+
+  if ((minBCoord == BLOCKDIR_ALIGN_FRAMES_NO_MINIMUM) ||
+      (maxBCoord == BLOCKDIR_ALIGN_FRAMES_NO_MAXIMUM)) {
+    minBCoord = maxBCoord = baselineBCoord;
+  }
+
+  if (psd != mRootSpan && zeroEffectiveSpanBox) {
+#ifdef NOISY_BLOCKDIR_ALIGN
+    printf("   [span]adjusting for zeroEffectiveSpanBox\n");
+    printf(
+        "     Original: minBCoord=%d, maxBCoord=%d, bSize=%d, ascent=%d, "
+        "logicalBSize=%d, topLeading=%d, bottomLeading=%d\n",
+        minBCoord, maxBCoord, spanFramePFD->mBounds.BSize(lineWM),
+        spanFramePFD->mAscent, psd->mLogicalBSize, psd->mBStartLeading,
+        psd->mBEndLeading);
+#endif
+    nscoord goodMinBCoord =
+        spanFramePFD->mBorderPadding.BStart(lineWM) - psd->mBStartLeading;
+    nscoord goodMaxBCoord = goodMinBCoord + psd->mLogicalBSize;
+
+    // For cases like the one in bug 714519 (text-decoration placement
+    // or making nsLineLayout::IsZeroBSize() handle
+    // vertical-align:top/bottom on a descendant of the line that's not
+    // a child of it), we want to treat elements that are
+    // vertical-align: top or bottom somewhat like children for the
+    // purposes of this quirk.  To some extent, this is guessing, since
+    // they might end up being aligned anywhere.  However, we'll guess
+    // that they'll be placed aligned with the top or bottom of this
+    // frame (as though this frame is the only thing in the line).
+    // (Guessing isn't unreasonable, since all we're doing is reducing the
+    // scope of a quirk and making the behavior more standards-like.)
+    if (maxStartBoxBSize > maxBCoord - minBCoord) {
+      // Distribute maxStartBoxBSize to ascent (baselineBCoord - minBCoord), and
+      // then to descent (maxBCoord - baselineBCoord) by adjusting minBCoord or
+      // maxBCoord, but not to exceed goodMinBCoord and goodMaxBCoord.
+      nscoord distribute = maxStartBoxBSize - (maxBCoord - minBCoord);
+      nscoord ascentSpace = std::max(minBCoord - goodMinBCoord, 0);
+      if (distribute > ascentSpace) {
+        distribute -= ascentSpace;
+        minBCoord -= ascentSpace;
+        nscoord descentSpace = std::max(goodMaxBCoord - maxBCoord, 0);
+        if (distribute > descentSpace) {
+          maxBCoord += descentSpace;
+        } else {
+          maxBCoord += distribute;
+        }
+      } else {
+        minBCoord -= distribute;
+      }
+    }
+    if (maxEndBoxBSize > maxBCoord - minBCoord) {
+      // Likewise, but preferring descent to ascent.
+      nscoord distribute = maxEndBoxBSize - (maxBCoord - minBCoord);
+      nscoord descentSpace = std::max(goodMaxBCoord - maxBCoord, 0);
+      if (distribute > descentSpace) {
+        distribute -= descentSpace;
+        maxBCoord += descentSpace;
+        nscoord ascentSpace = std::max(minBCoord - goodMinBCoord, 0);
+        if (distribute > ascentSpace) {
+          minBCoord -= ascentSpace;
+        } else {
+          minBCoord -= distribute;
+        }
+      } else {
+        maxBCoord += distribute;
+      }
+    }
+
+    if (minBCoord > goodMinBCoord) {
+      nscoord adjust = minBCoord - goodMinBCoord;  // positive
+
+      // shrink the logical extents
+      psd->mLogicalBSize -= adjust;
+      psd->mBStartLeading -= adjust;
+    }
+    if (maxBCoord < goodMaxBCoord) {
+      nscoord adjust = goodMaxBCoord - maxBCoord;
+      psd->mLogicalBSize -= adjust;
+      psd->mBEndLeading -= adjust;
+    }
+    if (minBCoord > 0) {
+      // shrink the content by moving its block start down.  This is tricky,
+      // since the block start is the 0 for many coordinates, so what we do is
+      // move everything else up.
+      spanFramePFD->mAscent -= minBCoord;  // move the baseline up
+      spanFramePFD->mBounds.BSize(lineWM) -=
+          minBCoord;  // move the block end up
+      psd->mBStartLeading += minBCoord;
+      *psd->mBaseline -= minBCoord;
+
+      pfd = psd->mFirstFrame;
+      while (nullptr != pfd) {
+        pfd->mBounds.BStart(lineWM) -= minBCoord;  // move all the children
+                                                   // back up
+        pfd->mFrame->SetRect(lineWM, pfd->mBounds, ContainerSizeForSpan(psd));
+        pfd = pfd->mNext;
+      }
+      maxBCoord -= minBCoord;  // since minBCoord is in the frame's own
+                               // coordinate system
+      minBCoord = 0;
+    }
+    if (maxBCoord < spanFramePFD->mBounds.BSize(lineWM)) {
+      nscoord adjust = spanFramePFD->mBounds.BSize(lineWM) - maxBCoord;
+      spanFramePFD->mBounds.BSize(lineWM) -= adjust;  // move the bottom up
+      psd->mBEndLeading += adjust;
+    }
+#ifdef NOISY_BLOCKDIR_ALIGN
+    printf(
+        "     New: minBCoord=%d, maxBCoord=%d, bSize=%d, ascent=%d, "
+        "logicalBSize=%d, topLeading=%d, bottomLeading=%d\n",
+        minBCoord, maxBCoord, spanFramePFD->mBounds.BSize(lineWM),
+        spanFramePFD->mAscent, psd->mLogicalBSize, psd->mBStartLeading,
+        psd->mBEndLeading);
+#endif
+  }
+
+  psd->mMinBCoord = minBCoord;
+  psd->mMaxBCoord = maxBCoord;
+#ifdef NOISY_BLOCKDIR_ALIGN
+  printf(
+      "  [span]==> minBCoord=%d maxBCoord=%d delta=%d maxStartBoxBSize=%d "
+      "maxEndBoxBSize=%d\n",
+      minBCoord, maxBCoord, maxBCoord - minBCoord, maxStartBoxBSize,
+      maxEndBoxBSize);
+#endif
+  if (maxStartBoxBSize > mMaxStartBoxBSize) {
+    mMaxStartBoxBSize = maxStartBoxBSize;
+  }
+  if (maxEndBoxBSize > mMaxEndBoxBSize) {
+    mMaxEndBoxBSize = maxEndBoxBSize;
+  }
+}
+
+static void SlideSpanFrameRect(nsIFrame* aFrame, nscoord aDeltaWidth) {
+  // This should not use nsIFrame::MovePositionBy because it happens
+  // prior to relative positioning.  In particular, because
+  // nsBlockFrame::PlaceLine calls aLineLayout.TrimTrailingWhiteSpace()
+  // prior to calling aLineLayout.RelativePositionFrames().
+  nsPoint p = aFrame->GetPosition();
+  p.x -= aDeltaWidth;
+  aFrame->SetPosition(p);
+}
+
+bool nsLineLayout::TrimTrailingWhiteSpaceIn(PerSpanData* psd,
+                                            nscoord* aDeltaISize) {
+  PerFrameData* pfd = psd->mFirstFrame;
+  if (!pfd) {
+    *aDeltaISize = 0;
+    return false;
+  }
+  pfd = pfd->Last();
+  while (nullptr != pfd) {
+#ifdef REALLY_NOISY_TRIM
+    psd->mFrame->mFrame->ListTag(stdout);
+    printf(": attempting trim of ");
+    pfd->mFrame->ListTag(stdout);
+    printf("\n");
+#endif
+    PerSpanData* childSpan = pfd->mSpan;
+    WritingMode lineWM = mRootSpan->mWritingMode;
+    if (childSpan) {
+      // Maybe the child span has the trailing white-space in it?
+      if (TrimTrailingWhiteSpaceIn(childSpan, aDeltaISize)) {
+        nscoord deltaISize = *aDeltaISize;
+        if (deltaISize) {
+          // Adjust the child spans frame size
+          pfd->mBounds.ISize(lineWM) -= deltaISize;
+          if (psd != mRootSpan) {
+            // When the child span is not a direct child of the block
+            // we need to update the child spans frame rectangle
+            // because it most likely will not be done again. Spans
+            // that are direct children of the block will be updated
+            // later, however, because the VerticalAlignFrames method
+            // will be run after this method.
+            nsSize containerSize = ContainerSizeForSpan(childSpan);
+            nsIFrame* f = pfd->mFrame;
+            LogicalRect r(lineWM, f->GetRect(), containerSize);
+            r.ISize(lineWM) -= deltaISize;
+            f->SetRect(lineWM, r, containerSize);
+          }
+
+          // Adjust the inline end edge of the span that contains the child span
+          psd->mICoord -= deltaISize;
+
+          // Slide any frames that follow the child span over by the
+          // correct amount. The only thing that can follow the child
+          // span is empty stuff, so we are just making things
+          // sensible (keeping the combined area honest).
+          while (pfd->mNext) {
+            pfd = pfd->mNext;
+            pfd->mBounds.IStart(lineWM) -= deltaISize;
+            if (psd != mRootSpan) {
+              // When the child span is not a direct child of the block
+              // we need to update the child span's frame rectangle
+              // because it most likely will not be done again. Spans
+              // that are direct children of the block will be updated
+              // later, however, because the VerticalAlignFrames method
+              // will be run after this method.
+              SlideSpanFrameRect(pfd->mFrame, deltaISize);
+            }
+          }
+        }
+        return true;
+      }
+    } else if (!pfd->mIsTextFrame && !pfd->mSkipWhenTrimmingWhitespace) {
+      // If we hit a frame on the end that's not text and not a placeholder,
+      // then there is no trailing whitespace to trim. Stop the search.
+      *aDeltaISize = 0;
+      return true;
+    } else if (pfd->mIsTextFrame) {
+      // Call TrimTrailingWhiteSpace even on empty textframes because they
+      // might have a soft hyphen which should now appear, changing the frame's
+      // width
+      nsTextFrame::TrimOutput trimOutput =
+          static_cast<nsTextFrame*>(pfd->mFrame)
+              ->TrimTrailingWhiteSpace(
+                  mLineContainerRI.mRenderingContext->GetDrawTarget());
+#ifdef NOISY_TRIM
+      psd->mFrame->mFrame->ListTag(stdout);
+      printf(": trim of ");
+      pfd->mFrame->ListTag(stdout);
+      printf(" returned %d\n", trimOutput.mDeltaWidth);
+#endif
+
+      if (trimOutput.mChanged) {
+        pfd->mRecomputeOverflow = true;
+      }
+
+      // Delta width not being zero means that
+      // there is trimmed space in the frame.
+      if (trimOutput.mDeltaWidth) {
+        pfd->mBounds.ISize(lineWM) -= trimOutput.mDeltaWidth;
+
+        // If any trailing space is trimmed, the justification opportunity
+        // generated by the space should be removed as well.
+        pfd->mJustificationInfo.CancelOpportunityForTrimmedSpace();
+
+        // See if the text frame has already been placed in its parent
+        if (psd != mRootSpan) {
+          // The frame was already placed during psd's
+          // reflow. Update the frames rectangle now.
+          pfd->mFrame->SetRect(lineWM, pfd->mBounds, ContainerSizeForSpan(psd));
+        }
+
+        // Adjust containing span's right edge
+        psd->mICoord -= trimOutput.mDeltaWidth;
+
+        // Slide any frames that follow the text frame over by the
+        // right amount. The only thing that can follow the text
+        // frame is empty stuff, so we are just making things
+        // sensible (keeping the combined area honest).
+        while (pfd->mNext) {
+          pfd = pfd->mNext;
+          pfd->mBounds.IStart(lineWM) -= trimOutput.mDeltaWidth;
+          if (psd != mRootSpan) {
+            // When the child span is not a direct child of the block
+            // we need to update the child spans frame rectangle
+            // because it most likely will not be done again. Spans
+            // that are direct children of the block will be updated
+            // later, however, because the VerticalAlignFrames method
+            // will be run after this method.
+            SlideSpanFrameRect(pfd->mFrame, trimOutput.mDeltaWidth);
+          }
+        }
+      }
+
+      if (pfd->mIsNonEmptyTextFrame || trimOutput.mChanged) {
+        // Pass up to caller so they can shrink their span
+        *aDeltaISize = trimOutput.mDeltaWidth;
+        return true;
+      }
+    }
+    pfd = pfd->mPrev;
+  }
+
+  *aDeltaISize = 0;
+  return false;
+}
+
+bool nsLineLayout::TrimTrailingWhiteSpace() {
+  PerSpanData* psd = mRootSpan;
+  nscoord deltaISize;
+  TrimTrailingWhiteSpaceIn(psd, &deltaISize);
+  return 0 != deltaISize;
+}
+
+bool nsLineLayout::PerFrameData::ParticipatesInJustification() const {
+  if (mIsMarker || mIsEmpty || mSkipWhenTrimmingWhitespace) {
+    // Skip ::markers, empty frames, and placeholders
+    return false;
+  }
+  if (mIsTextFrame && !mIsNonWhitespaceTextFrame &&
+      static_cast<nsTextFrame*>(mFrame)->IsAtEndOfLine()) {
+    // Skip trimmed whitespaces
+    return false;
+  }
+  return true;
+}
+
+struct nsLineLayout::JustificationComputationState {
+  PerFrameData* mFirstParticipant;
+  PerFrameData* mLastParticipant;
+  // When we are going across a boundary of ruby base, i.e. entering
+  // one, leaving one, or both, the following fields will be set to
+  // the corresponding ruby base frame for handling ruby-align.
+  PerFrameData* mLastExitedRubyBase;
+  PerFrameData* mLastEnteredRubyBase;
+
+  JustificationComputationState()
+      : mFirstParticipant(nullptr),
+        mLastParticipant(nullptr),
+        mLastExitedRubyBase(nullptr),
+        mLastEnteredRubyBase(nullptr) {}
+};
+
+static bool IsRubyAlignSpaceAround(nsIFrame* aRubyBase) {
+  return aRubyBase->StyleText()->mRubyAlign == StyleRubyAlign::SpaceAround;
+}
+
+/**
+ * Assign justification gaps for justification
+ * opportunities across two frames.
+ */
+/* static */
+int nsLineLayout::AssignInterframeJustificationGaps(
+    PerFrameData* aFrame, JustificationComputationState& aState) {
+  PerFrameData* prev = aState.mLastParticipant;
+  MOZ_ASSERT(prev);
+
+  auto& assign = aFrame->mJustificationAssignment;
+  auto& prevAssign = prev->mJustificationAssignment;
+
+  if (aState.mLastExitedRubyBase || aState.mLastEnteredRubyBase) {
+    PerFrameData* exitedRubyBase = aState.mLastExitedRubyBase;
+    if (!exitedRubyBase || IsRubyAlignSpaceAround(exitedRubyBase->mFrame)) {
+      prevAssign.mGapsAtEnd = 1;
+    } else {
+      exitedRubyBase->mJustificationAssignment.mGapsAtEnd = 1;
+    }
+
+    PerFrameData* enteredRubyBase = aState.mLastEnteredRubyBase;
+    if (!enteredRubyBase || IsRubyAlignSpaceAround(enteredRubyBase->mFrame)) {
+      assign.mGapsAtStart = 1;
+    } else {
+      enteredRubyBase->mJustificationAssignment.mGapsAtStart = 1;
+    }
+
+    // We are no longer going across a ruby base boundary.
+    aState.mLastExitedRubyBase = nullptr;
+    aState.mLastEnteredRubyBase = nullptr;
+    return 1;
+  }
+
+  const auto& info = aFrame->mJustificationInfo;
+  const auto& prevInfo = prev->mJustificationInfo;
+  if (!info.mIsStartJustifiable && !prevInfo.mIsEndJustifiable) {
+    return 0;
+  }
+
+  if (!info.mIsStartJustifiable) {
+    prevAssign.mGapsAtEnd = 2;
+    assign.mGapsAtStart = 0;
+  } else if (!prevInfo.mIsEndJustifiable) {
+    prevAssign.mGapsAtEnd = 0;
+    assign.mGapsAtStart = 2;
+  } else {
+    prevAssign.mGapsAtEnd = 1;
+    assign.mGapsAtStart = 1;
+  }
+  return 1;
+}
+
+/**
+ * Compute the justification info of the given span, and store the
+ * number of inner opportunities into the frame's justification info.
+ * It returns the number of non-inner opportunities it detects.
+ */
+int32_t nsLineLayout::ComputeFrameJustification(
+    PerSpanData* aPSD, JustificationComputationState& aState) {
+  NS_ASSERTION(aPSD, "null arg");
+  NS_ASSERTION(!aState.mLastParticipant || !aState.mLastParticipant->mSpan,
+               "Last participant shall always be a leaf frame");
+  bool firstChild = true;
+  int32_t& innerOpportunities =
+      aPSD->mFrame->mJustificationInfo.mInnerOpportunities;
+  MOZ_ASSERT(innerOpportunities == 0,
+             "Justification info should not have been set yet.");
+  int32_t outerOpportunities = 0;
+
+  for (PerFrameData* pfd = aPSD->mFirstFrame; pfd; pfd = pfd->mNext) {
+    if (!pfd->ParticipatesInJustification()) {
+      continue;
+    }
+
+    bool isRubyBase = pfd->mFrame->IsRubyBaseFrame();
+    PerFrameData* outerRubyBase = aState.mLastEnteredRubyBase;
+    if (isRubyBase) {
+      aState.mLastEnteredRubyBase = pfd;
+    }
+
+    int extraOpportunities = 0;
+    if (pfd->mSpan) {
+      PerSpanData* span = pfd->mSpan;
+      extraOpportunities = ComputeFrameJustification(span, aState);
+      innerOpportunities += pfd->mJustificationInfo.mInnerOpportunities;
+    } else {
+      if (pfd->mIsTextFrame) {
+        innerOpportunities += pfd->mJustificationInfo.mInnerOpportunities;
+      }
+
+      if (!aState.mLastParticipant) {
+        aState.mFirstParticipant = pfd;
+        // It is not an empty ruby base, but we are not assigning gaps
+        // to the content for now. Clear the last entered ruby base so
+        // that we can correctly set the last exited ruby base.
+        aState.mLastEnteredRubyBase = nullptr;
+      } else {
+        extraOpportunities = AssignInterframeJustificationGaps(pfd, aState);
+      }
+
+      aState.mLastParticipant = pfd;
+    }
+
+    if (isRubyBase) {
+      if (aState.mLastEnteredRubyBase == pfd) {
+        // There is no justification participant inside this ruby base.
+        // Ignore this ruby base completely and restore the outer ruby
+        // base here.
+        aState.mLastEnteredRubyBase = outerRubyBase;
+      } else {
+        aState.mLastExitedRubyBase = pfd;
+      }
+    }
+
+    if (firstChild) {
+      outerOpportunities = extraOpportunities;
+      firstChild = false;
+    } else {
+      innerOpportunities += extraOpportunities;
+    }
+  }
+
+  return outerOpportunities;
+}
+
+void nsLineLayout::AdvanceAnnotationInlineBounds(PerFrameData* aPFD,
+                                                 const nsSize& aContainerSize,
+                                                 nscoord aDeltaICoord,
+                                                 nscoord aDeltaISize) {
+  nsIFrame* frame = aPFD->mFrame;
+  LayoutFrameType frameType = frame->Type();
+  MOZ_ASSERT(frameType == LayoutFrameType::RubyText ||
+             frameType == LayoutFrameType::RubyTextContainer);
+  MOZ_ASSERT(aPFD->mSpan, "rt and rtc should have span.");
+
+  PerSpanData* psd = aPFD->mSpan;
+  WritingMode lineWM = mRootSpan->mWritingMode;
+  aPFD->mBounds.IStart(lineWM) += aDeltaICoord;
+
+  // Check whether this expansion should be counted into the reserved
+  // isize or not. When it is a ruby text container, and it has some
+  // children linked to the base, it must not have reserved isize,
+  // or its children won't align with their bases.  Otherwise, this
+  // expansion should be reserved.  There are two cases a ruby text
+  // container does not have children linked to the base:
+  // 1. it is a container for span; 2. its children are collapsed.
+  // See bug 1055674 for the second case.
+  if (frameType == LayoutFrameType::RubyText ||
+      // This ruby text container is a span.
+      (psd->mFirstFrame == psd->mLastFrame && psd->mFirstFrame &&
+       !psd->mFirstFrame->mIsLinkedToBase)) {
+    // For ruby text frames, only increase frames
+    // which are not auto-hidden.
+    if (frameType != LayoutFrameType::RubyText ||
+        !static_cast<nsRubyTextFrame*>(frame)->IsCollapsed()) {
+      nscoord reservedISize = RubyUtils::GetReservedISize(frame);
+      RubyUtils::SetReservedISize(frame, reservedISize + aDeltaISize);
+    }
+  } else {
+    // It is a normal ruby text container. Its children will expand
+    // themselves properly. We only need to expand its own size here.
+    aPFD->mBounds.ISize(lineWM) += aDeltaISize;
+  }
+  aPFD->mFrame->SetRect(lineWM, aPFD->mBounds, aContainerSize);
+}
+
+/**
+ * This function applies the changes of icoord and isize caused by
+ * justification to annotations of the given frame.
+ */
+void nsLineLayout::ApplyLineJustificationToAnnotations(PerFrameData* aPFD,
+                                                       nscoord aDeltaICoord,
+                                                       nscoord aDeltaISize) {
+  PerFrameData* pfd = aPFD->mNextAnnotation;
+  while (pfd) {
+    nsSize containerSize = pfd->mFrame->GetParent()->GetSize();
+    AdvanceAnnotationInlineBounds(pfd, containerSize, aDeltaICoord,
+                                  aDeltaISize);
+
+    // There are two cases where an annotation frame has siblings which
+    // do not attached to a ruby base-level frame:
+    // 1. there's an intra-annotation whitespace which has no intra-base
+    //    white-space to pair with;
+    // 2. there are not enough ruby bases to be paired with annotations.
+    // In these cases, their size should not be affected, but we still
+    // need to move them so that they won't overlap other frames.
+    PerFrameData* sibling = pfd->mNext;
+    while (sibling && !sibling->mIsLinkedToBase) {
+      AdvanceAnnotationInlineBounds(sibling, containerSize,
+                                    aDeltaICoord + aDeltaISize, 0);
+      sibling = sibling->mNext;
+    }
+
+    pfd = pfd->mNextAnnotation;
+  }
+}
+
+nscoord nsLineLayout::ApplyFrameJustification(
+    PerSpanData* aPSD, JustificationApplicationState& aState) {
+  NS_ASSERTION(aPSD, "null arg");
+
+  nscoord deltaICoord = 0;
+  for (PerFrameData* pfd = aPSD->mFirstFrame; pfd != nullptr;
+       pfd = pfd->mNext) {
+    nscoord dw = 0;
+    WritingMode lineWM = mRootSpan->mWritingMode;
+    const auto& assign = pfd->mJustificationAssignment;
+    bool isInlineText =
+        pfd->mIsTextFrame && !pfd->mWritingMode.IsOrthogonalTo(lineWM);
+
+    // Don't apply justification if the frame doesn't participate. Same
+    // as the condition used in ComputeFrameJustification. Note that,
+    // we still need to move the frame based on deltaICoord even if the
+    // frame itself doesn't expand.
+    if (pfd->ParticipatesInJustification()) {
+      if (isInlineText) {
+        if (aState.IsJustifiable()) {
+          // Set corresponding justification gaps here, so that the
+          // text frame knows how it should add gaps at its sides.
+          const auto& info = pfd->mJustificationInfo;
+          auto textFrame = static_cast<nsTextFrame*>(pfd->mFrame);
+          textFrame->AssignJustificationGaps(assign);
+          dw = aState.Consume(JustificationUtils::CountGaps(info, assign));
+        }
+
+        if (dw) {
+          pfd->mRecomputeOverflow = true;
+        }
+      } else {
+        if (nullptr != pfd->mSpan) {
+          dw = ApplyFrameJustification(pfd->mSpan, aState);
+        }
+      }
+    } else {
+      MOZ_ASSERT(!assign.TotalGaps(),
+                 "Non-participants shouldn't have assigned gaps");
+    }
+
+    pfd->mBounds.ISize(lineWM) += dw;
+    nscoord gapsAtEnd = 0;
+    if (!isInlineText && assign.TotalGaps()) {
+      // It is possible that we assign gaps to non-text frame or an
+      // orthogonal text frame. Apply the gaps as margin for them.
+      deltaICoord += aState.Consume(assign.mGapsAtStart);
+      gapsAtEnd = aState.Consume(assign.mGapsAtEnd);
+      dw += gapsAtEnd;
+    }
+    pfd->mBounds.IStart(lineWM) += deltaICoord;
+
+    // The gaps added to the end of the frame should also be
+    // excluded from the isize added to the annotation.
+    ApplyLineJustificationToAnnotations(pfd, deltaICoord, dw - gapsAtEnd);
+    deltaICoord += dw;
+    pfd->mFrame->SetRect(lineWM, pfd->mBounds, ContainerSizeForSpan(aPSD));
+  }
+  return deltaICoord;
+}
+
+static nsIFrame* FindNearestRubyBaseAncestor(nsIFrame* aFrame) {
+  MOZ_ASSERT(aFrame->Style()->ShouldSuppressLineBreak());
+  while (aFrame && !aFrame->IsRubyBaseFrame()) {
+    aFrame = aFrame->GetParent();
+  }
+  // XXX It is possible that no ruby base ancestor is found because of
+  // some edge cases like form control or canvas inside ruby text.
+  // See bug 1138092 comment 4.
+  NS_WARNING_ASSERTION(aFrame, "no ruby base ancestor?");
+  return aFrame;
+}
+
+/**
+ * This method expands the given frame by the given reserved isize.
+ */
+void nsLineLayout::ExpandRubyBox(PerFrameData* aFrame, nscoord aReservedISize,
+                                 const nsSize& aContainerSize) {
+  WritingMode lineWM = mRootSpan->mWritingMode;
+  auto rubyAlign = aFrame->mFrame->StyleText()->mRubyAlign;
+  switch (rubyAlign) {
+    case StyleRubyAlign::Start:
+      // do nothing for start
+      break;
+    case StyleRubyAlign::SpaceBetween:
+    case StyleRubyAlign::SpaceAround: {
+      int32_t opportunities = aFrame->mJustificationInfo.mInnerOpportunities;
+      int32_t gaps = opportunities * 2;
+      if (rubyAlign == StyleRubyAlign::SpaceAround) {
+        // Each expandable ruby box with ruby-align space-around has a
+        // gap at each of its sides. For rb/rbc, see comment in
+        // AssignInterframeJustificationGaps; for rt/rtc, see comment
+        // in ExpandRubyBoxWithAnnotations.
+        gaps += 2;
+      }
+      if (gaps > 0) {
+        JustificationApplicationState state(gaps, aReservedISize);
+        ApplyFrameJustification(aFrame->mSpan, state);
+        break;
+      }
+      // If there are no justification opportunities for space-between,
+      // fall-through to center per spec.
+      [[fallthrough]];
+    }
+    case StyleRubyAlign::Center:
+      // Indent all children by half of the reserved inline size.
+      for (PerFrameData* child = aFrame->mSpan->mFirstFrame; child;
+           child = child->mNext) {
+        child->mBounds.IStart(lineWM) += aReservedISize / 2;
+        child->mFrame->SetRect(lineWM, child->mBounds, aContainerSize);
+      }
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("Unknown ruby-align value");
+  }
+
+  aFrame->mBounds.ISize(lineWM) += aReservedISize;
+  aFrame->mFrame->SetRect(lineWM, aFrame->mBounds, aContainerSize);
+}
+
+/**
+ * This method expands the given frame by the reserved inline size.
+ * It also expands its annotations if they are expandable and have
+ * reserved isize larger than zero.
+ */
+void nsLineLayout::ExpandRubyBoxWithAnnotations(PerFrameData* aFrame,
+                                                const nsSize& aContainerSize) {
+  nscoord reservedISize = RubyUtils::GetReservedISize(aFrame->mFrame);
+  if (reservedISize) {
+    ExpandRubyBox(aFrame, reservedISize, aContainerSize);
+  }
+
+  WritingMode lineWM = mRootSpan->mWritingMode;
+  bool isLevelContainer = aFrame->mFrame->IsRubyBaseContainerFrame();
+  for (PerFrameData* annotation = aFrame->mNextAnnotation; annotation;
+       annotation = annotation->mNextAnnotation) {
+    if (lineWM.IsOrthogonalTo(annotation->mFrame->GetWritingMode())) {
+      // Inter-character case: don't attempt to expand ruby annotations.
+      continue;
+    }
+    if (isLevelContainer) {
+      nsIFrame* rtcFrame = annotation->mFrame;
+      MOZ_ASSERT(rtcFrame->IsRubyTextContainerFrame());
+      // It is necessary to set the rect again because the container
+      // width was unknown, and zero was used instead when we reflow
+      // them. The corresponding base containers were repositioned in
+      // VerticalAlignFrames and PlaceTopBottomFrames.
+      MOZ_ASSERT(rtcFrame->GetLogicalSize(lineWM) ==
+                 annotation->mBounds.Size(lineWM));
+      rtcFrame->SetPosition(lineWM, annotation->mBounds.Origin(lineWM),
+                            aContainerSize);
+    }
+
+    nscoord reservedISize = RubyUtils::GetReservedISize(annotation->mFrame);
+    if (!reservedISize) {
+      continue;
+    }
+
+    MOZ_ASSERT(annotation->mSpan);
+    JustificationComputationState computeState;
+    ComputeFrameJustification(annotation->mSpan, computeState);
+    if (!computeState.mFirstParticipant) {
+      continue;
+    }
+    if (IsRubyAlignSpaceAround(annotation->mFrame)) {
+      // Add one gap at each side of this annotation.
+      computeState.mFirstParticipant->mJustificationAssignment.mGapsAtStart = 1;
+      computeState.mLastParticipant->mJustificationAssignment.mGapsAtEnd = 1;
+    }
+    nsIFrame* parentFrame = annotation->mFrame->GetParent();
+    nsSize containerSize = parentFrame->GetSize();
+    MOZ_ASSERT(containerSize == aContainerSize ||
+                   parentFrame->IsRubyTextContainerFrame(),
+               "Container width should only be different when the current "
+               "annotation is a ruby text frame, whose parent is not same "
+               "as its base frame.");
+    ExpandRubyBox(annotation, reservedISize, containerSize);
+    ExpandInlineRubyBoxes(annotation->mSpan);
+  }
+}
+
+/**
+ * This method looks for all expandable ruby box in the given span, and
+ * calls ExpandRubyBox to expand them in depth-first preorder.
+ */
+void nsLineLayout::ExpandInlineRubyBoxes(PerSpanData* aSpan) {
+  nsSize containerSize = ContainerSizeForSpan(aSpan);
+  for (PerFrameData* pfd = aSpan->mFirstFrame; pfd; pfd = pfd->mNext) {
+    if (RubyUtils::IsExpandableRubyBox(pfd->mFrame)) {
+      ExpandRubyBoxWithAnnotations(pfd, containerSize);
+    }
+    if (pfd->mSpan) {
+      ExpandInlineRubyBoxes(pfd->mSpan);
+    }
+  }
+}
+
+nscoord nsLineLayout::GetHangFrom(const PerSpanData* aSpan,
+                                  bool aLineIsRTL) const {
+  const PerFrameData* pfd = aSpan->mLastFrame;
+  nscoord result = 0;
+  while (pfd) {
+    if (const PerSpanData* childSpan = pfd->mSpan) {
+      return GetHangFrom(childSpan, aLineIsRTL);
+    }
+    if (pfd->mIsTextFrame) {
+      auto* lastText = static_cast<nsTextFrame*>(pfd->mFrame);
+      result = lastText->GetHangableISize();
+      if (result) {
+        // If the hangable space will be at the start edge of the line, due to
+        // its bidi direction being against the line direction, we flag this by
+        // negating the advance.
+        lastText->EnsureTextRun(nsTextFrame::eInflated);
+        auto* textRun = lastText->GetTextRun(nsTextFrame::eInflated);
+        if (textRun && textRun->IsRightToLeft() != aLineIsRTL) {
+          result = -result;
+        }
+      }
+      return result;
+    }
+    if (!pfd->mSkipWhenTrimmingWhitespace) {
+      // If we hit a frame on the end that's not text and not a placeholder or
+      // <br>, then there is no trailing whitespace to hang. Stop the search.
+      return result;
+    }
+    // Scan back for a preceding frame whose whitespace we can hang.
+    pfd = pfd->mPrev;
+  }
+  return result;
+}
+
+gfxTextRun::TrimmableWS nsLineLayout::GetTrimFrom(const PerSpanData* aSpan,
+                                                  bool aLineIsRTL) const {
+  const PerFrameData* pfd = aSpan->mLastFrame;
+  while (pfd) {
+    if (const PerSpanData* childSpan = pfd->mSpan) {
+      return GetTrimFrom(childSpan, aLineIsRTL);
+    }
+    if (pfd->mIsTextFrame) {
+      auto* lastText = static_cast<nsTextFrame*>(pfd->mFrame);
+      auto result = lastText->GetTrimmableWS();
+      if (result.mAdvance) {
+        lastText->EnsureTextRun(nsTextFrame::eInflated);
+        auto* textRun = lastText->GetTextRun(nsTextFrame::eInflated);
+        if (textRun && textRun->IsRightToLeft() != aLineIsRTL) {
+          result.mAdvance = -result.mAdvance;
+        }
+      }
+      return result;
+    }
+    if (!pfd->mSkipWhenTrimmingWhitespace) {
+      // If we hit a frame on the end that's not text and not a placeholder or
+      // <br>, then there is no trailing whitespace to trim. Stop the search.
+      return gfxTextRun::TrimmableWS{};
+    }
+    // Scan back for a preceding frame whose whitespace we can trim.
+    pfd = pfd->mPrev;
+  }
+  return gfxTextRun::TrimmableWS{};
+}
+
+// Align inline frames within the line according to the CSS text-align
+// property.
+void nsLineLayout::TextAlignLine(nsLineBox* aLine, bool aIsLastLine) {
+  /**
+   * NOTE: aIsLastLine ain't necessarily so: it is correctly set by caller
+   * only in cases where the last line needs special handling.
+   */
+  PerSpanData* psd = mRootSpan;
+  WritingMode lineWM = psd->mWritingMode;
+  LAYOUT_WARN_IF_FALSE(psd->mIEnd != NS_UNCONSTRAINEDSIZE,
+                       "have unconstrained width; this should only result from "
+                       "very large sizes, not attempts at intrinsic width "
+                       "calculation");
+  nscoord availISize = psd->mIEnd - psd->mIStart;
+  nscoord remainingISize = availISize - aLine->ISize();
+#ifdef NOISY_INLINEDIR_ALIGN
+  LineContainerFrame()->ListTag(stdout);
+  printf(": availISize=%d lineBounds.IStart=%d lineISize=%d delta=%d\n",
+         availISize, aLine->IStart(), aLine->ISize(), remainingISize);
+#endif
+
+  nscoord dx = 0;
+  StyleTextAlign textAlign =
+      aIsLastLine ? mStyleText->TextAlignForLastLine() : mStyleText->mTextAlign;
+
+  // Check if there's trailing whitespace we need to "hang" at line-wrap.
+  nscoord hang = 0;
+  uint32_t trimCount = 0;
+  if (aLine->IsLineWrapped()) {
+    if (textAlign == StyleTextAlign::Justify) {
+      auto trim = GetTrimFrom(mRootSpan, lineWM.IsBidiRTL());
+      hang = NSToCoordRound(trim.mAdvance);
+      trimCount = trim.mCount;
+    } else {
+      hang = GetHangFrom(mRootSpan, lineWM.IsBidiRTL());
+    }
+  }
+
+  bool isSVG = LineContainerFrame()->IsInSVGTextSubtree();
+  bool doTextAlign = remainingISize > 0 || hang != 0;
+
+  int32_t additionalGaps = 0;
+  if (!isSVG &&
+      (mHasRuby || (doTextAlign && textAlign == StyleTextAlign::Justify))) {
+    JustificationComputationState computeState;
+    ComputeFrameJustification(psd, computeState);
+    if (mHasRuby && computeState.mFirstParticipant) {
+      PerFrameData* firstFrame = computeState.mFirstParticipant;
+      if (firstFrame->mFrame->Style()->ShouldSuppressLineBreak()) {
+        MOZ_ASSERT(!firstFrame->mJustificationAssignment.mGapsAtStart);
+        nsIFrame* rubyBase = FindNearestRubyBaseAncestor(firstFrame->mFrame);
+        if (rubyBase && IsRubyAlignSpaceAround(rubyBase)) {
+          firstFrame->mJustificationAssignment.mGapsAtStart = 1;
+          additionalGaps++;
+        }
+      }
+      PerFrameData* lastFrame = computeState.mLastParticipant;
+      if (lastFrame->mFrame->Style()->ShouldSuppressLineBreak()) {
+        MOZ_ASSERT(!lastFrame->mJustificationAssignment.mGapsAtEnd);
+        nsIFrame* rubyBase = FindNearestRubyBaseAncestor(lastFrame->mFrame);
+        if (rubyBase && IsRubyAlignSpaceAround(rubyBase)) {
+          lastFrame->mJustificationAssignment.mGapsAtEnd = 1;
+          additionalGaps++;
+        }
+      }
+    }
+  }
+
+  if (!isSVG && doTextAlign) {
+    switch (textAlign) {
+      case StyleTextAlign::Justify: {
+        int32_t opportunities =
+            psd->mFrame->mJustificationInfo.mInnerOpportunities -
+            (hang ? trimCount : 0);
+        if (opportunities > 0) {
+          int32_t gaps = opportunities * 2 + additionalGaps;
+          remainingISize += std::abs(hang);
+          JustificationApplicationState applyState(gaps, remainingISize);
+
+          // Apply the justification, and make sure to update our linebox
+          // width to account for it.
+          aLine->ExpandBy(ApplyFrameJustification(psd, applyState),
+                          ContainerSizeForSpan(psd));
+
+          // If the trimmable trailing whitespace that we want to hang had
+          // reverse-inline directionality, adjust line position to account for
+          // it being at the inline-start side.
+          // On top of the original "hang" amount, justification will have
+          // modified its width, so we include that adjustment here.
+          if (hang < 0) {
+            dx = hang - trimCount * remainingISize / opportunities;
+          }
+
+          // Gaps that belong to trimmed whitespace were not included in the
+          // applyState count, so we need to add them here for the assert.
+          DebugOnly<int32_t> trimmedGaps = hang ? trimCount * 2 : 0;
+          MOZ_ASSERT(applyState.mGaps.mHandled ==
+                         applyState.mGaps.mCount + trimmedGaps,
+                     "Unprocessed justification gaps");
+          // Similarly, account for the adjustment applied to the trimmed
+          // whitespace, which is in addition to the adjustment that applies
+          // within the actual width of the line.
+          DebugOnly<int32_t> trimmedAdjustment =
+              trimCount * remainingISize / opportunities;
+          NS_ASSERTION(applyState.mWidth.mConsumed ==
+                           applyState.mWidth.mAvailable + trimmedAdjustment,
+                       "Unprocessed justification width");
+          break;
+        }
+        // Fall through to the default case if we could not justify to fill
+        // the space.
+        [[fallthrough]];
+      }
+
+      case StyleTextAlign::Start:
+      case StyleTextAlign::Char:
+        // Default alignment is to start edge so do nothing, except to apply
+        // any "reverse-hang" amount resulting from reversed-direction trailing
+        // space.
+        // Char is for tables so treat as start if we find it in block layout.
+        if (hang < 0) {
+          dx = hang;
+        }
+        break;
+
+      case StyleTextAlign::Left:
+      case StyleTextAlign::MozLeft:
+        if (lineWM.IsBidiRTL()) {
+          dx = remainingISize + (hang > 0 ? hang : 0);
+        } else if (hang < 0) {
+          dx = hang;
+        }
+        break;
+
+      case StyleTextAlign::Right:
+      case StyleTextAlign::MozRight:
+        if (lineWM.IsBidiLTR()) {
+          dx = remainingISize + (hang > 0 ? hang : 0);
+        } else if (hang < 0) {
+          dx = hang;
+        }
+        break;
+
+      case StyleTextAlign::End:
+        dx = remainingISize + (hang > 0 ? hang : 0);
+        break;
+
+      case StyleTextAlign::Center:
+      case StyleTextAlign::MozCenter:
+        dx = (remainingISize + hang) / 2;
+        break;
+    }
+  }
+
+  if (mHasRuby) {
+    ExpandInlineRubyBoxes(mRootSpan);
+  }
+
+  PerFrameData* startFrame = psd->mFirstFrame;
+  MOZ_ASSERT(startFrame, "empty line?");
+  if (startFrame->mIsMarker) {
+    // ::marker shouldn't participate in bidi reordering nor text alignment.
+    startFrame = startFrame->mNext;
+    MOZ_ASSERT(startFrame, "no frame after ::marker?");
+    MOZ_ASSERT(!startFrame->mIsMarker, "multiple ::markers?");
+  }
+
+  const bool bidi = mPresContext->BidiEnabled() &&
+                    (!mPresContext->IsVisualMode() || lineWM.IsBidiRTL());
+  if (bidi) {
+    nsBidiPresUtils::ReorderFrames(startFrame->mFrame, aLine->GetChildCount(),
+                                   lineWM, mContainerSize,
+                                   psd->mIStart + mTextIndent + dx);
+  }
+
+  if (dx) {
+    // For the bidi case, if startFrame is a ::first-line frame, the mIStart and
+    // mTextIndent offsets will already have been applied to its position, but
+    // we still need to apply the text-align adjustment |dx| to its position.
+    const bool needToAdjustFrames = !bidi || startFrame->mFrame->IsLineFrame();
+    MOZ_ASSERT_IF(startFrame->mFrame->IsLineFrame(), !startFrame->mNext);
+    if (needToAdjustFrames) {
+      for (PerFrameData* pfd = startFrame; pfd; pfd = pfd->mNext) {
+        pfd->mBounds.IStart(lineWM) += dx;
+        pfd->mFrame->SetRect(lineWM, pfd->mBounds, ContainerSizeForSpan(psd));
+      }
+    }
+    aLine->IndentBy(dx, ContainerSize());
+  }
+}
+
+// This method applies any relative positioning to the given frame.
+void nsLineLayout::ApplyRelativePositioning(PerFrameData* aPFD) {
+  if (!aPFD->mIsRelativelyOrStickyPos) {
+    return;
+  }
+
+  nsIFrame* frame = aPFD->mFrame;
+  WritingMode frameWM = aPFD->mWritingMode;
+  LogicalPoint origin = frame->GetLogicalPosition(ContainerSize());
+  // right and bottom are handled by
+  // ReflowInput::ComputeRelativeOffsets
+  ReflowInput::ApplyRelativePositioning(frame, frameWM, aPFD->mOffsets, &origin,
+                                        ContainerSize());
+  frame->SetPosition(frameWM, origin, ContainerSize());
+}
+
+// This method do relative positioning for ruby annotations.
+void nsLineLayout::RelativePositionAnnotations(PerSpanData* aRubyPSD,
+                                               OverflowAreas& aOverflowAreas) {
+  MOZ_ASSERT(aRubyPSD->mFrame->mFrame->IsRubyFrame());
+  for (PerFrameData* pfd = aRubyPSD->mFirstFrame; pfd; pfd = pfd->mNext) {
+    MOZ_ASSERT(pfd->mFrame->IsRubyBaseContainerFrame());
+    for (PerFrameData* rtc = pfd->mNextAnnotation; rtc;
+         rtc = rtc->mNextAnnotation) {
+      nsIFrame* rtcFrame = rtc->mFrame;
+      MOZ_ASSERT(rtcFrame->IsRubyTextContainerFrame());
+      ApplyRelativePositioning(rtc);
+      OverflowAreas rtcOverflowAreas;
+      RelativePositionFrames(rtc->mSpan, rtcOverflowAreas);
+      aOverflowAreas.UnionWith(rtcOverflowAreas + rtcFrame->GetPosition());
+    }
+  }
+}
+
+void nsLineLayout::RelativePositionFrames(PerSpanData* psd,
+                                          OverflowAreas& aOverflowAreas) {
+  OverflowAreas overflowAreas;
+  WritingMode wm = psd->mWritingMode;
+  if (psd != mRootSpan) {
+    // The span's overflow areas come in three parts:
+    // -- this frame's width and height
+    // -- pfd->mOverflowAreas, which is the area of a ::marker or the union
+    // of a relatively positioned frame's absolute children
+    // -- the bounds of all inline descendants
+    // The former two parts are computed right here, we gather the descendants
+    // below.
+    // At this point psd->mFrame->mBounds might be out of date since
+    // bidi reordering can move and resize the frames. So use the frame's
+    // rect instead of mBounds.
+    nsRect adjustedBounds(nsPoint(0, 0), psd->mFrame->mFrame->GetSize());
+
+    overflowAreas.ScrollableOverflow().UnionRect(
+        psd->mFrame->mOverflowAreas.ScrollableOverflow(), adjustedBounds);
+    overflowAreas.InkOverflow().UnionRect(
+        psd->mFrame->mOverflowAreas.InkOverflow(), adjustedBounds);
+  } else {
+    LogicalRect rect(wm, psd->mIStart, mBStartEdge, psd->mICoord - psd->mIStart,
+                     mFinalLineBSize);
+    // The minimum combined area for the frames that are direct
+    // children of the block starts at the upper left corner of the
+    // line and is sized to match the size of the line's bounding box
+    // (the same size as the values returned from VerticalAlignFrames)
+    overflowAreas.InkOverflow() = rect.GetPhysicalRect(wm, ContainerSize());
+    overflowAreas.ScrollableOverflow() = overflowAreas.InkOverflow();
+  }
+
+  for (PerFrameData* pfd = psd->mFirstFrame; pfd; pfd = pfd->mNext) {
+    nsIFrame* frame = pfd->mFrame;
+
+    // Adjust the origin of the frame
+    ApplyRelativePositioning(pfd);
+
+    // We must position the view correctly before positioning its
+    // descendants so that widgets are positioned properly (since only
+    // some views have widgets).
+    if (frame->HasView())
+      nsContainerFrame::SyncFrameViewAfterReflow(
+          mPresContext, frame, frame->GetView(),
+          pfd->mOverflowAreas.InkOverflow(),
+          nsIFrame::ReflowChildFlags::NoSizeView);
+
+    // Note: the combined area of a child is in its coordinate
+    // system. We adjust the childs combined area into our coordinate
+    // system before computing the aggregated value by adding in
+    // <b>x</b> and <b>y</b> which were computed above.
+    OverflowAreas r;
+    if (pfd->mSpan) {
+      // Compute a new combined area for the child span before
+      // aggregating it into our combined area.
+      RelativePositionFrames(pfd->mSpan, r);
+    } else {
+      r = pfd->mOverflowAreas;
+      if (pfd->mIsTextFrame) {
+        // We need to recompute overflow areas in four cases:
+        // (1) When PFD_RECOMPUTEOVERFLOW is set due to trimming
+        // (2) When there are text decorations, since we can't recompute the
+        //     overflow area until Reflow and VerticalAlignLine have finished
+        // (3) When there are text emphasis marks, since the marks may be
+        //     put further away if the text is inside ruby.
+        // (4) When there are text strokes
+        if (pfd->mRecomputeOverflow ||
+            frame->Style()->HasTextDecorationLines() ||
+            frame->StyleText()->HasEffectiveTextEmphasis() ||
+            frame->StyleText()->HasWebkitTextStroke()) {
+          nsTextFrame* f = static_cast<nsTextFrame*>(frame);
+          r = f->RecomputeOverflow(LineContainerFrame());
+        }
+        frame->FinishAndStoreOverflow(r, frame->GetSize());
+      }
+
+      // If we have something that's not an inline but with a complex frame
+      // hierarchy inside that contains views, they need to be
+      // positioned.
+      // All descendant views must be repositioned even if this frame
+      // does have a view in case this frame's view does not have a
+      // widget and some of the descendant views do have widgets --
+      // otherwise the widgets won't be repositioned.
+      nsContainerFrame::PositionChildViews(frame);
+    }
+
+    // Do this here (rather than along with setting the overflow rect
+    // below) so we get leaf frames as well.  No need to worry
+    // about the root span, since it doesn't have a frame.
+    if (frame->HasView())
+      nsContainerFrame::SyncFrameViewAfterReflow(
+          mPresContext, frame, frame->GetView(), r.InkOverflow(),
+          nsIFrame::ReflowChildFlags::NoMoveView);
+
+    overflowAreas.UnionWith(r + frame->GetPosition());
+  }
+
+  // Also compute relative position in the annotations.
+  if (psd->mFrame->mFrame->IsRubyFrame()) {
+    RelativePositionAnnotations(psd, overflowAreas);
+  }
+
+  // If we just computed a spans combined area, we need to update its
+  // overflow rect...
+  if (psd != mRootSpan) {
+    PerFrameData* spanPFD = psd->mFrame;
+    nsIFrame* frame = spanPFD->mFrame;
+    frame->FinishAndStoreOverflow(overflowAreas, frame->GetSize());
+  }
+  aOverflowAreas = overflowAreas;
+}