Font::drawGlyphs() cleanup

Font::drawGlyphs() is a fallback/legacy code path, only used in
drawGlyphBuffer() when we fail to build text blobs due to
verticalAnyUpright text.  Hence, the existing horizontal optimization is
no longer reachable.

Remove the dead code and associated helper method.

Also

  * fold the remaining paintGlyphs helper into drawGlyphs
  * drop unused textBounds param
  * use a scoped SkAutoCanvasRestore instead of explicit restore

No functional changes.

R=eae@chromium.org,drott@chromium.org,jbroman@chromium.org

Review URL: https://codereview.chromium.org/1548333002

Cr-Commit-Position: refs/heads/master@{#367011}

third_party/WebKit/Source/platform/fonts/Font.cpp

@@ -637,45 +637,19 @@ int Font::emphasisMarkHeight(const AtomicString& mark) const
     return markFontData->fontMetrics().height();
 }
 
-void Font::paintGlyphs(SkCanvas* canvas, const SkPaint& paint, const SimpleFontData* font,
-    const Glyph glyphs[], unsigned numGlyphs,
-    const SkPoint pos[], const FloatRect& textRect, float deviceScaleFactor) const
-{
-    SkPaint fontPaint(paint);
-    font->platformData().setupPaint(&fontPaint, deviceScaleFactor, this);
-    fontPaint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
-    canvas->drawPosText(glyphs, numGlyphs * sizeof(Glyph), pos, fontPaint);
-}
-
-void Font::paintGlyphsHorizontal(SkCanvas* canvas, const SkPaint& paint, const SimpleFontData* font,
-    const Glyph glyphs[], unsigned numGlyphs,
-    const SkScalar xpos[], SkScalar constY, const FloatRect& textRect, float deviceScaleFactor) const
-{
-    SkPaint fontPaint(paint);
-    font->platformData().setupPaint(&fontPaint, deviceScaleFactor, this);
-    fontPaint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
-    canvas->drawPosTextH(glyphs, numGlyphs * sizeof(Glyph), xpos, constY, fontPaint);
-}
-
 void Font::drawGlyphs(SkCanvas* canvas, const SkPaint& paint, const SimpleFontData* font,
     const GlyphBuffer& glyphBuffer, unsigned from, unsigned numGlyphs,
-    const FloatPoint& point, const FloatRect& textRect, float deviceScaleFactor) const
+    const FloatPoint& point, float deviceScaleFactor) const
 {
     ASSERT(glyphBuffer.size() >= from + numGlyphs);
 
-    if (!glyphBuffer.hasVerticalOffsets()) {
-        Vector<SkScalar, 64> xpos(numGlyphs);
-        for (unsigned i = 0; i < numGlyphs; i++)
-            xpos[i] = SkFloatToScalar(point.x() + glyphBuffer.xOffsetAt(from + i));
-
-        paintGlyphsHorizontal(canvas, paint, font, glyphBuffer.glyphs(from), numGlyphs, xpos.data(),
-            SkFloatToScalar(point.y()), textRect, deviceScaleFactor);
-        return;
-    }
+    // We only ever reach this fallback code path when failing to build a text blob due to
+    // verticalAnyUpright text in the buffer => the buffer is guaranteed to store vertical offsets.
+    ASSERT(glyphBuffer.hasVerticalOffsets());
 
     bool drawVertically = font->platformData().isVerticalAnyUpright() && font->verticalData();
 
-    int canvasStackLevel = canvas->getSaveCount();
+    SkAutoCanvasRestore autoRestore(canvas, false);
     if (drawVertically) {
         canvas->save();
         canvas->concat(affineTransformToSkMatrix(AffineTransform(0, -1, 1, 0, point.x(), point.y())));
@@ -684,7 +658,6 @@ void Font::drawGlyphs(SkCanvas* canvas, const SkPaint& paint, const SimpleFontDa
 
     const float verticalBaselineXOffset = drawVertically ? SkFloatToScalar(font->fontMetrics().floatAscent() - font->fontMetrics().floatAscent(IdeographicBaseline)) : 0;
 
-    ASSERT(glyphBuffer.hasVerticalOffsets());
     Vector<SkPoint, 32> pos(numGlyphs);
     for (unsigned i = 0; i < numGlyphs; i++) {
         pos[i].set(
@@ -692,8 +665,10 @@ void Font::drawGlyphs(SkCanvas* canvas, const SkPaint& paint, const SimpleFontDa
             SkFloatToScalar(point.y() + glyphBuffer.yOffsetAt(from + i)));
     }
 
-    paintGlyphs(canvas, paint, font, glyphBuffer.glyphs(from), numGlyphs, pos.data(), textRect, deviceScaleFactor);
-    canvas->restoreToCount(canvasStackLevel);
+    SkPaint fontPaint(paint);
+    font->platformData().setupPaint(&fontPaint, deviceScaleFactor, this);
+    fontPaint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
+    canvas->drawPosText(glyphBuffer.glyphs(from), numGlyphs * sizeof(Glyph), pos.data(), fontPaint);
 }
 
 void Font::drawTextBlob(SkCanvas* canvas, const SkPaint& paint, const SkTextBlob* blob, const SkPoint& origin) const
@@ -747,13 +722,13 @@ void Font::drawGlyphBuffer(SkCanvas* canvas, const SkPaint& paint, const TextRun
         const SimpleFontData* nextFontData = glyphBuffer.fontDataAt(nextGlyph);
 
         if (nextFontData != fontData) {
-            drawGlyphs(canvas, paint, fontData, glyphBuffer, lastFrom, nextGlyph - lastFrom, point, runInfo.bounds, deviceScaleFactor);
+            drawGlyphs(canvas, paint, fontData, glyphBuffer, lastFrom, nextGlyph - lastFrom, point, deviceScaleFactor);
             lastFrom = nextGlyph;
             fontData = nextFontData;
         }
     }
 
-    drawGlyphs(canvas, paint, fontData, glyphBuffer, lastFrom, nextGlyph - lastFrom, point, runInfo.bounds, deviceScaleFactor);
+    drawGlyphs(canvas, paint, fontData, glyphBuffer, lastFrom, nextGlyph - lastFrom, point, deviceScaleFactor);
 }
 
 float Font::floatWidthForSimpleText(const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts, FloatRect* glyphBounds) const

third_party/WebKit/Source/platform/fonts/Font.h

@@ -125,12 +125,8 @@ private:
     // Returns the total advance.
     float buildGlyphBuffer(const TextRunPaintInfo&, GlyphBuffer&, const GlyphData* emphasisData = nullptr) const;
     PassTextBlobPtr buildTextBlob(const GlyphBuffer&) const;
-    void paintGlyphs(SkCanvas*, const SkPaint&, const SimpleFontData*, const Glyph glyphs[], unsigned numGlyphs,
-        const SkPoint pos[], const FloatRect& textRect, float deviceScaleFactor) const;
-    void paintGlyphsHorizontal(SkCanvas*, const SkPaint&, const SimpleFontData*, const Glyph glyphs[], unsigned numGlyphs,
-        const SkScalar xpos[], SkScalar constY, const FloatRect& textRect, float deviceScaleFactor) const;
-    void drawGlyphs(SkCanvas*, const SkPaint&, const SimpleFontData*, const GlyphBuffer&, unsigned from, unsigned numGlyphs,
-        const FloatPoint&, const FloatRect& textRect, float deviceScaleFactor) const;
+    void drawGlyphs(SkCanvas*, const SkPaint&, const SimpleFontData*, const GlyphBuffer&,
+        unsigned from, unsigned numGlyphs, const FloatPoint&, float deviceScaleFactor) const;
     void drawTextBlob(SkCanvas*, const SkPaint&, const SkTextBlob*, const SkPoint& origin) const;
     void drawGlyphBuffer(SkCanvas*, const SkPaint&, const TextRunPaintInfo&, const GlyphBuffer&, const FloatPoint&, float deviceScaleFactor) const;
     float floatWidthForSimpleText(const TextRun&, HashSet<const SimpleFontData*>* fallbackFonts = 0, FloatRect* glyphBounds = 0) const;