diff --git a/src/core/SkGlyphRun.cpp b/src/core/SkGlyphRun.cpp
index ec5479c..9ae21c0 100644
--- a/src/core/SkGlyphRun.cpp
+++ b/src/core/SkGlyphRun.cpp
@@ -30,12 +30,16 @@
 // -- SkGlyphRun -----------------------------------------------------------------------------------
 SkGlyphRun::SkGlyphRun(const SkPaint& basePaint,
                        const SkRunFont& runFont,
+                       SkSpan<const uint16_t> denseIndices,
                        SkSpan<const SkPoint> positions,
                        SkSpan<const SkGlyphID> glyphIDs,
+                       SkSpan<const SkGlyphID> uniqueGlyphIDs,
                        SkSpan<const char> text,
                        SkSpan<const uint32_t> clusters)
-        : fPositions{positions}
+        : fUniqueGlyphIDIndices{denseIndices}
+        , fPositions{positions}
         , fGlyphIDs{glyphIDs}
+        , fUniqueGlyphIDs{uniqueGlyphIDs}
         , fText{text}
         , fClusters{clusters}
         , fRunPaint{basePaint, runFont} {}
@@ -46,8 +50,10 @@
     SkGlyphRun run{
         fRunPaint,
         SkRunFont{fRunPaint},
+        SkSpan<const uint16_t>{},  // No dense indices for now.
         SkSpan<const SkPoint>{&point, 1},
         SkSpan<const SkGlyphID>{&glyphID, 1},
+        SkSpan<const SkGlyphID>{},
         SkSpan<const char>{},
         SkSpan<const uint32_t>{}
     };
@@ -192,6 +198,8 @@
             SkRunFont{paint},
             glyphIDs,
             positions,
+            SkSpan<const uint16_t>{},  // no dense indices for now.,
+            SkSpan<const SkGlyphID>{},
             SkSpan<const char>{},
             SkSpan<const uint32_t>{});
     this->makeGlyphRunList(paint, nullptr, SkPoint::Make(0, 0));
@@ -202,7 +210,8 @@
     auto glyphIDs = textToGlyphIDs(paint, bytes, byteLength);
     if (!glyphIDs.empty()) {
         this->initialize(glyphIDs.size());
-        this->simplifyDrawText(paint, SkRunFont{paint}, glyphIDs, origin, fPositions);
+        this->simplifyDrawText(paint, SkRunFont{paint}, glyphIDs, origin,
+                               fUniqueGlyphIDIndices, fUniqueGlyphIDs, fPositions);
     }
 
     this->makeGlyphRunList(paint, nullptr, SkPoint::Make(0, 0));
@@ -215,7 +224,8 @@
     if (!glyphIDs.empty()) {
         this->initialize(glyphIDs.size());
         this->simplifyDrawPosTextH(
-                paint, SkRunFont{paint}, glyphIDs, xpos, constY, fPositions);
+                paint, SkRunFont{paint}, glyphIDs, xpos, constY,
+                fUniqueGlyphIDIndices, fUniqueGlyphIDs, fPositions);
     }
 
     this->makeGlyphRunList(paint, nullptr, SkPoint::Make(0, 0));
@@ -226,7 +236,8 @@
     auto glyphIDs = textToGlyphIDs(paint, bytes, byteLength);
     if (!glyphIDs.empty()) {
         this->initialize(glyphIDs.size());
-        this->simplifyDrawPosText(paint, SkRunFont{paint}, glyphIDs, pos);
+        this->simplifyDrawPosText(paint, SkRunFont{paint}, glyphIDs, pos,
+                fUniqueGlyphIDIndices, fUniqueGlyphIDs);
     }
 
     this->makeGlyphRunList(paint, nullptr, SkPoint::Make(0, 0));
@@ -242,7 +253,9 @@
     // Pre-size all the buffers so they don't move during processing.
     this->initialize(totalGlyphs);
 
+    uint16_t* currentDenseIndices = fUniqueGlyphIDIndices;
     SkPoint* currentPositions = fPositions;
+    SkGlyphID* currentUniqueGlyphIDs = fUniqueGlyphIDs;
 
     for (SkTextBlobRunIterator it(&blob); !it.done(); it.next()) {
         // applyFontToPaint() always overwrites the exact same attributes,
@@ -254,28 +267,34 @@
         const SkPoint& offset = it.offset();
         auto glyphIDs = SkSpan<const SkGlyphID>{it.glyphs(), runSize};
 
+        size_t uniqueGlyphIDsSize = 0;
         switch (it.positioning()) {
             case SkTextBlobRunIterator::kDefault_Positioning: {
-                this->simplifyDrawText(
-                        paint, it.runFont(), glyphIDs, offset, currentPositions,
+                uniqueGlyphIDsSize = this->simplifyDrawText(
+                        paint, it.runFont(), glyphIDs, offset,
+                        currentDenseIndices, currentUniqueGlyphIDs, currentPositions,
                         text, clusters);
             }
                 break;
             case SkTextBlobRunIterator::kHorizontal_Positioning: {
                 auto constY = offset.y();
-                this->simplifyDrawPosTextH(
-                        paint, it.runFont(), glyphIDs, it.pos(), constY, currentPositions,
+                uniqueGlyphIDsSize = this->simplifyDrawPosTextH(
+                        paint, it.runFont(), glyphIDs, it.pos(), constY,
+                        currentDenseIndices, currentUniqueGlyphIDs, currentPositions,
                         text, clusters);
             }
                 break;
             case SkTextBlobRunIterator::kFull_Positioning:
-                this->simplifyDrawPosText(
+                uniqueGlyphIDsSize = this->simplifyDrawPosText(
                         paint, it.runFont(), glyphIDs, (const SkPoint*)it.pos(),
+                        currentDenseIndices, currentUniqueGlyphIDs,
                         text, clusters);
                 break;
         }
 
+        currentDenseIndices += runSize;
         currentPositions += runSize;
+        currentUniqueGlyphIDs += uniqueGlyphIDsSize;
     }
 
     this->makeGlyphRunList(paint, &blob, origin);
@@ -285,7 +304,8 @@
         const SkPaint& paint, SkSpan<const SkGlyphID> glyphIDs, const SkPoint* pos) {
     if (!glyphIDs.empty()) {
         this->initialize(glyphIDs.size());
-        this->simplifyDrawPosText(paint, SkRunFont{paint}, glyphIDs, pos);
+        this->simplifyDrawPosText(paint, SkRunFont{paint}, glyphIDs, pos,
+                                  fUniqueGlyphIDIndices, fUniqueGlyphIDs);
         this->makeGlyphRunList(paint, nullptr, SkPoint::Make(0, 0));
     }
 }
@@ -298,7 +318,9 @@
 
     if (totalRunSize > fMaxTotalRunSize) {
         fMaxTotalRunSize = totalRunSize;
+        fUniqueGlyphIDIndices.reset(fMaxTotalRunSize);
         fPositions.reset(fMaxTotalRunSize);
+        fUniqueGlyphIDs.reset(fMaxTotalRunSize);
     }
 
     fGlyphRunListStorage.clear();
@@ -324,11 +346,33 @@
     }
 }
 
+SkSpan<const SkGlyphID> SkGlyphRunBuilder::addDenseAndUnique(
+        const SkPaint& paint,
+        SkSpan<const SkGlyphID> glyphIDs,
+        uint16_t* uniqueGlyphIDIndices,
+        SkGlyphID* uniqueGlyphIDs) {
+    SkSpan<const SkGlyphID> uniquifiedGlyphIDs;
+    if (!glyphIDs.empty()) {
+        auto typeface = SkPaintPriv::GetTypefaceOrDefault(paint);
+        auto glyphUniverseSize = typeface->countGlyphs();
+
+        // There better be glyphs in the font if we want to uniqify.
+        if (glyphUniverseSize > 0) {
+            uniquifiedGlyphIDs = fGlyphIDSet.uniquifyGlyphIDs(
+                    glyphUniverseSize, glyphIDs, uniqueGlyphIDs, uniqueGlyphIDIndices);
+        }
+    }
+
+    return uniquifiedGlyphIDs;
+}
+
 void SkGlyphRunBuilder::makeGlyphRun(
         const SkPaint& basePaint,
         const SkRunFont& runFont,
         SkSpan<const SkGlyphID> glyphIDs,
         SkSpan<const SkPoint> positions,
+        SkSpan<const uint16_t> uniqueGlyphIDIndices,
+        SkSpan<const SkGlyphID> uniqueGlyphIDs,
         SkSpan<const char> text,
         SkSpan<const uint32_t> clusters) {
 
@@ -337,8 +381,10 @@
         fGlyphRunListStorage.emplace_back(
                 basePaint,
                 runFont,
+                uniqueGlyphIDIndices,
                 positions,
                 glyphIDs,
+                uniqueGlyphIDs,
                 text,
                 clusters);
     }
@@ -352,53 +398,62 @@
         paint, blob, origin, SkSpan<SkGlyphRun>{fGlyphRunListStorage}};
 }
 
-SkPoint SkGlyphRunBuilder::simplifyDrawText(
+size_t SkGlyphRunBuilder::simplifyDrawText(
         const SkPaint& paint, const SkRunFont& runFont, SkSpan<const SkGlyphID> glyphIDs,
-        SkPoint origin, SkPoint* positions,
-        SkSpan<const char> text, SkSpan<const uint32_t> clusters) {
+        SkPoint origin, uint16_t* uniqueGlyphIDIndicesBuffer, SkGlyphID* uniqueGlyphIDsBuffer,
+        SkPoint* positions, SkSpan<const char> text, SkSpan<const uint32_t> clusters) {
     SkASSERT(!glyphIDs.empty());
 
     auto runSize = glyphIDs.size();
 
     SkPaint runPaint{paint, runFont};
 
-    fScratchAdvances.resize(runSize);
-    {
-        auto cache = SkStrikeCache::FindOrCreateStrikeExclusive(runPaint);
-        cache->getAdvances(glyphIDs, fScratchAdvances.data());
-    }
+    auto unqiueGlyphIDs = this->addDenseAndUnique(
+            runPaint, glyphIDs, uniqueGlyphIDIndicesBuffer, uniqueGlyphIDsBuffer);
 
-    SkPoint endOfLastGlyph = origin;
-
-    for (size_t i = 0; i < runSize; i++) {
-        positions[i] = endOfLastGlyph;
-        endOfLastGlyph += fScratchAdvances[i];
-    }
-
-    if (paint.getTextAlign() != SkPaint::kLeft_Align) {
-        SkVector len = endOfLastGlyph - origin;
-        if (paint.getTextAlign() == SkPaint::kCenter_Align) {
-            len.scale(SK_ScalarHalf);
+    if (!unqiueGlyphIDs.empty()) {
+        fScratchAdvances.resize(runSize);
+        {
+            auto cache = SkStrikeCache::FindOrCreateStrikeExclusive(runPaint);
+            cache->getAdvances(unqiueGlyphIDs, fScratchAdvances.data());
         }
-        for (auto& pt : SkSpan<SkPoint>{positions, runSize}) {
-            pt -= len;
+
+        SkPoint endOfLastGlyph = origin;
+
+        for (size_t i = 0; i < runSize; i++) {
+            positions[i] = endOfLastGlyph;
+            endOfLastGlyph += fScratchAdvances[uniqueGlyphIDIndicesBuffer[i]];
         }
+
+        if (paint.getTextAlign() != SkPaint::kLeft_Align) {
+            SkVector len = endOfLastGlyph - origin;
+            if (paint.getTextAlign() == SkPaint::kCenter_Align) {
+                len.scale(SK_ScalarHalf);
+            }
+            for (auto& pt : SkSpan<SkPoint>{positions, runSize}) {
+                pt -= len;
+            }
+
+        }
+
+        this->makeGlyphRun(
+                paint,
+                runFont,
+                glyphIDs,
+                SkSpan<const SkPoint>{positions, runSize},
+                SkSpan<const uint16_t>{uniqueGlyphIDIndicesBuffer, runSize},
+                unqiueGlyphIDs,
+                text,
+                clusters);
     }
 
-    this->makeGlyphRun(
-            paint,
-            runFont,
-            glyphIDs,
-            SkSpan<const SkPoint>{positions, runSize},
-            text,
-            clusters);
-
-    return endOfLastGlyph;
+    return unqiueGlyphIDs.size();
 }
 
-void SkGlyphRunBuilder::simplifyDrawPosTextH(
+size_t SkGlyphRunBuilder::simplifyDrawPosTextH(
         const SkPaint& paint, const SkRunFont& runFont, SkSpan<const SkGlyphID> glyphIDs,
-        const SkScalar* xpos, SkScalar constY, SkPoint* positions,
+        const SkScalar* xpos, SkScalar constY,
+        uint16_t* uniqueGlyphIDIndicesBuffer, SkGlyphID* uniqueGlyphIDsBuffer, SkPoint* positions,
         SkSpan<const char> text, SkSpan<const uint32_t> clusters) {
 
     auto posCursor = positions;
@@ -406,19 +461,34 @@
         *posCursor++ = SkPoint::Make(x, constY);
     }
 
-    simplifyDrawPosText(paint, runFont, glyphIDs, positions, text, clusters);
+    return simplifyDrawPosText(paint, runFont, glyphIDs, positions,
+            uniqueGlyphIDIndicesBuffer, uniqueGlyphIDsBuffer,
+            text, clusters);
 }
 
-void SkGlyphRunBuilder::simplifyDrawPosText(
+size_t SkGlyphRunBuilder::simplifyDrawPosText(
         const SkPaint& paint, const SkRunFont& runFont, SkSpan<const SkGlyphID> glyphIDs,
-        const SkPoint* pos, SkSpan<const char> text, SkSpan<const uint32_t> clusters) {
+        const SkPoint* pos, uint16_t* uniqueGlyphIDIndicesBuffer, SkGlyphID* uniqueGlyphIDsBuffer,
+        SkSpan<const char> text, SkSpan<const uint32_t> clusters) {
     auto runSize = glyphIDs.size();
 
+    // The dense indices are not used by the rest of the stack yet.
+    SkSpan<const SkGlyphID> uniqueGlyphIDs;
+    #ifdef SK_DEBUG
+        uniqueGlyphIDs = this->addDenseAndUnique(
+                paint, glyphIDs, uniqueGlyphIDIndicesBuffer, uniqueGlyphIDsBuffer);
+    #endif
+
+    // TODO: when using the unique glyph system have a guard that there are actually glyphs like
+    // drawText above.
     this->makeGlyphRun(
             paint,
             runFont,
             glyphIDs,
             SkSpan<const SkPoint>{pos, runSize},
+            SkSpan<const SkGlyphID>{uniqueGlyphIDIndicesBuffer, runSize},
+            uniqueGlyphIDs,
             text,
             clusters);
+    return uniqueGlyphIDs.size();
 }
diff --git a/src/core/SkGlyphRun.h b/src/core/SkGlyphRun.h
index d5abb6a..2d0d345 100644
--- a/src/core/SkGlyphRun.h
+++ b/src/core/SkGlyphRun.h
@@ -87,8 +87,10 @@
     SkGlyphRun() = default;
     SkGlyphRun(const SkPaint& basePaint,
                const SkRunFont& runFont,
+               SkSpan<const uint16_t> denseIndices,
                SkSpan<const SkPoint> positions,
                SkSpan<const SkGlyphID> glyphIDs,
+               SkSpan<const SkGlyphID> uniqueGlyphIDs,
                SkSpan<const char> text,
                SkSpan<const uint32_t> clusters);
 
@@ -105,17 +107,21 @@
 
     size_t runSize() const { return fGlyphIDs.size(); }
     SkSpan<const SkPoint> positions() const { return fPositions.toConst(); }
-    SkSpan<const SkGlyphID> glyphsIDs() const { return fGlyphIDs; }
+    SkSpan<const SkGlyphID> shuntGlyphsIDs() const { return fGlyphIDs; }
     const SkPaint& paint() const { return fRunPaint; }
     SkPaint* mutablePaint() { return &fRunPaint; }
     SkSpan<const uint32_t> clusters() const { return fClusters; }
     SkSpan<const char> text() const { return fText; }
 
 private:
-    // Positions relative to the list's origin.
+    //
+    const SkSpan<const uint16_t> fUniqueGlyphIDIndices;
+    //
     const SkSpan<const SkPoint> fPositions;
     // This is temporary while converting from the old per glyph code to the bulk code.
     const SkSpan<const SkGlyphID> fGlyphIDs;
+    // The unique glyphs from fGlyphIDs.
+    const SkSpan<const SkGlyphID> fUniqueGlyphIDs;
     // Original text from SkTextBlob if present. Will be empty of not present.
     const SkSpan<const char> fText;
     // Original clusters from SkTextBlob if present. Will be empty if not present.
@@ -134,7 +140,6 @@
 
 public:
     SkGlyphRunList();
-
     // Blob maybe null.
     SkGlyphRunList(
             const SkPaint& paint,
@@ -203,45 +208,61 @@
     SkSpan<const SkGlyphID> textToGlyphIDs(
             const SkPaint& paint, const void* bytes, size_t byteLength);
 
+    // Returns the span of unique glyph IDs.
+    SkSpan<const SkGlyphID> addDenseAndUnique(
+            const SkPaint& paint,
+            SkSpan<const SkGlyphID> glyphIDs,
+            uint16_t* uniqueGlyphIDIndices,
+            SkGlyphID* uniqueGlyphIDs);
+
     void makeGlyphRun(
             const SkPaint& basePaint,
             const SkRunFont& runFont,
             SkSpan<const SkGlyphID> glyphIDs,
             SkSpan<const SkPoint> positions,
+            SkSpan<const uint16_t> uniqueGlyphIDIndices,
+            SkSpan<const SkGlyphID> uniqueGlyphIDs,
             SkSpan<const char> text,
             SkSpan<const uint32_t> clusters);
 
     void makeGlyphRunList(const SkPaint& paint, const SkTextBlob* blob, SkPoint origin);
 
-    // Return the end of the last glyph for measurement.
-    SkPoint simplifyDrawText(
+    size_t simplifyDrawText(
             const SkPaint& paint, const SkRunFont& runFont, SkSpan<const SkGlyphID> glyphIDs,
-            SkPoint origin, SkPoint* positions,
+            SkPoint origin,uint16_t* uniqueGlyphIDIndices, SkGlyphID* uniqueGlyphIDs,
+            SkPoint* positions,
             SkSpan<const char> text = SkSpan<const char>{},
             SkSpan<const uint32_t> clusters = SkSpan<const uint32_t>{});
-    void simplifyDrawPosTextH(
+    size_t simplifyDrawPosTextH(
             const SkPaint& paint, const SkRunFont& runFont, SkSpan<const SkGlyphID> glyphIDs,
-            const SkScalar* xpos, SkScalar constY, SkPoint* positions,
+            const SkScalar* xpos, SkScalar constY,
+            uint16_t* uniqueGlyphIDIndices, SkGlyphID* uniqueGlyphIDs, SkPoint* positions,
             SkSpan<const char> text = SkSpan<const char>{},
             SkSpan<const uint32_t> clusters = SkSpan<const uint32_t>{});
-    void simplifyDrawPosText(
+    size_t simplifyDrawPosText(
             const SkPaint& paint, const SkRunFont& runFont, SkSpan<const SkGlyphID> glyphIDs,
-            const SkPoint* pos,
+            const SkPoint* pos, uint16_t* uniqueGlyphIDIndices, SkGlyphID* uniqueGlyphIDs,
             SkSpan<const char> text = SkSpan<const char>{},
             SkSpan<const uint32_t> clusters = SkSpan<const uint32_t>{});
 
     size_t fMaxTotalRunSize{0};
+    SkAutoTMalloc<uint16_t> fUniqueGlyphIDIndices;
     SkAutoTMalloc<SkPoint> fPositions;
+    SkAutoTMalloc<SkGlyphID> fUniqueGlyphIDs;
 
     std::vector<SkGlyphRun> fGlyphRunListStorage;
     SkGlyphRunList fGlyphRunList;
 
+
     // Used as a temporary for preparing using utfN text. This implies that only one run of
     // glyph ids will ever be needed because blobs are already glyph based.
     std::vector<SkGlyphID> fScratchGlyphIDs;
 
     // Used as temporary storage for calculating positions for drawText.
     std::vector<SkPoint> fScratchAdvances;
+
+    // Used for collecting the set of unique glyphs.
+    SkGlyphIDSet fGlyphIDSet;
 };
 
 template <typename PerGlyphPos>
diff --git a/src/core/SkGlyphRunPainter.cpp b/src/core/SkGlyphRunPainter.cpp
index 44c94c0..cfaafe3 100644
--- a/src/core/SkGlyphRunPainter.cpp
+++ b/src/core/SkGlyphRunPainter.cpp
@@ -153,7 +153,7 @@
         matrix.mapPoints(fPositions, glyphRun.positions().data(), runSize);
 
         const SkPoint* positionCursor = fPositions;
-        for (auto glyphID : glyphRun.glyphsIDs()) {
+        for (auto glyphID : glyphRun.shuntGlyphsIDs()) {
             auto position = *positionCursor++;
             if (SkScalarsAreFinite(position.fX, position.fY)) {
                 const SkGlyph& glyph = cache->getGlyphMetrics(glyphID, position);
@@ -181,7 +181,7 @@
         matrix.mapPoints(fPositions, glyphRun.positions().data(), runSize);
 
         const SkPoint* positionCursor = fPositions;
-        for (auto glyphID : glyphRun.glyphsIDs()) {
+        for (auto glyphID : glyphRun.shuntGlyphsIDs()) {
             auto position = *positionCursor++;
             if (SkScalarsAreFinite(position.fX, position.fY)) {
                 const SkGlyph& glyph = cache->getGlyphIDMetrics(glyphID);
diff --git a/src/core/SkGlyphRunPainter.h b/src/core/SkGlyphRunPainter.h
index 7840604..3e7129a 100644
--- a/src/core/SkGlyphRunPainter.h
+++ b/src/core/SkGlyphRunPainter.h
@@ -150,7 +150,7 @@
         mapping.mapPoints(fPositions, glyphRun.positions().data(), runSize);
         const SkPoint* mappedPtCursor = fPositions;
         const SkPoint* ptCursor = glyphRun.positions().data();
-        for (auto glyphID : glyphRun.glyphsIDs()) {
+        for (auto glyphID : glyphRun.shuntGlyphsIDs()) {
             auto mappedPt = *mappedPtCursor++;
             auto pt = origin + *ptCursor++;
             if (SkScalarsAreFinite(mappedPt.x(), mappedPt.y())) {
@@ -234,7 +234,7 @@
     SkScalar maxFallbackDimension{-SK_ScalarInfinity};
 
     const SkPoint* positionCursor = glyphRun.positions().data();
-    for (auto glyphID : glyphRun.glyphsIDs()) {
+    for (auto glyphID : glyphRun.shuntGlyphsIDs()) {
         const SkGlyph& glyph = cache->getGlyphMetrics(glyphID, {0, 0});
         SkPoint glyphPos = origin + *positionCursor++;
         if (glyph.fMaskFormat == SkMask::kSDF_Format || glyph.isEmpty()) {
diff --git a/src/pdf/SkClusterator.cpp b/src/pdf/SkClusterator.cpp
index 2827810..f575407 100644
--- a/src/pdf/SkClusterator.cpp
+++ b/src/pdf/SkClusterator.cpp
@@ -28,7 +28,7 @@
 SkClusterator::SkClusterator(const SkGlyphRun& run)
     : fClusters(run.clusters().data())
     , fUtf8Text(run.text().data())
-    , fGlyphCount(SkToU32(run.glyphsIDs().size()))
+    , fGlyphCount(SkToU32(run.shuntGlyphsIDs().size()))
     , fTextByteLength(SkToU32(run.text().size()))
 {
     if (fClusters) {
diff --git a/src/pdf/SkPDFDevice.cpp b/src/pdf/SkPDFDevice.cpp
index 20bbcdd..4415c34 100644
--- a/src/pdf/SkPDFDevice.cpp
+++ b/src/pdf/SkPDFDevice.cpp
@@ -1038,8 +1038,8 @@
     SkPath path;
     SkASSERT(paint.getTextEncoding() == SkPaint::kGlyphID_TextEncoding);
 
-    paint.getPosTextPath(glyphRun.glyphsIDs().data(),
-                         glyphRun.glyphsIDs().size() * sizeof(SkGlyphID),
+    paint.getPosTextPath(glyphRun.shuntGlyphsIDs().data(),
+                         glyphRun.shuntGlyphsIDs().size() * sizeof(SkGlyphID),
                          glyphRun.positions().data(),
                          &path);
     path.offset(offset.x(), offset.y());
@@ -1088,8 +1088,8 @@
 
 void SkPDFDevice::internalDrawGlyphRun(const SkGlyphRun& glyphRun, SkPoint offset) {
 
-    const SkGlyphID* glyphs = glyphRun.glyphsIDs().data();
-    uint32_t glyphCount = SkToU32(glyphRun.glyphsIDs().size());
+    const SkGlyphID* glyphs = glyphRun.shuntGlyphsIDs().data();
+    uint32_t glyphCount = SkToU32(glyphRun.shuntGlyphsIDs().size());
     SkPaint srcPaint{glyphRun.paint()};
     srcPaint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
     srcPaint.setTextAlign(SkPaint::kLeft_Align);
diff --git a/src/svg/SkSVGDevice.cpp b/src/svg/SkSVGDevice.cpp
index f85b9a9..ffb4723 100644
--- a/src/svg/SkSVGDevice.cpp
+++ b/src/svg/SkSVGDevice.cpp
@@ -872,7 +872,7 @@
         const SkPaint& paint = glyphRun.paint();
         auto runSize = glyphRun.runSize();
         SkAutoSTArray<64, SkUnichar> unichars(runSize);
-        paint.glyphsToUnichars(glyphRun.glyphsIDs().data(), runSize, unichars.get());
+        paint.glyphsToUnichars(glyphRun.shuntGlyphsIDs().data(), runSize, unichars.get());
         auto positions = glyphRun.positions();
         for (size_t i = 0; i < runSize; ++i) {
             this->appendUnichar(unichars[i], positions[i]);
diff --git a/tests/PDFPrimitivesTest.cpp b/tests/PDFPrimitivesTest.cpp
index 60450eb..9b97b03 100644
--- a/tests/PDFPrimitivesTest.cpp
+++ b/tests/PDFPrimitivesTest.cpp
@@ -493,8 +493,10 @@
                            SkPaint paint, const uint32_t* clusters,
                            size_t utf8TextByteLength, const char* utf8Text) {
     return SkGlyphRun(paint, SkRunFont{paint},
+                      SkSpan<const uint16_t>{},  // No dense indices for now.
                       SkSpan<const SkPoint>{pos, len},
                       SkSpan<const SkGlyphID>{glyphs, len},
+                      SkSpan<const SkGlyphID>{},
                       SkSpan<const char>{utf8Text, utf8TextByteLength},
                       SkSpan<const uint32_t>{clusters, len});
 }