Track the region where text is painted.

Source/core/platform/graphics/skia/FontSkia.cpp

 /*
  * Copyright (c) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 71 matching lines @@
     
     if (font->fontDescription().textRenderingMode() == GeometricPrecision)
         paint->setHinting(SkPaint::kNo_Hinting);
 }
 
 // TODO: This needs to be split into helper functions to better scope the
 // inputs/outputs, and reduce duplicate code.
 // This issue is tracked in https://bugs.webkit.org/show_bug.cgi?id=62989
 void Font::drawGlyphs(GraphicsContext* gc, const SimpleFontData* font,
                       const GlyphBuffer& glyphBuffer,  int from, int numGlyphs,
-                      const FloatPoint& point) const {
+                      const FloatPoint& point, const FloatRect& textRect) const {
     COMPILE_ASSERT(sizeof(GlyphBufferGlyph) == sizeof(uint16_t), GlyphBufferGlyphSize_equals_uint16_t);
 
     bool shouldSmoothFonts = true;
     bool shouldAntialias = true;
 
     switch (fontDescription().fontSmoothing()) {
     case Antialiased:
         shouldSmoothFonts = false;
         break;
     case SubpixelAntialiased:
@@ skipping 44 matching lines @@
     TextDrawingModeFlags textMode = gc->platformContext()->getTextDrawingMode();
 
     // We draw text up to two times (once for fill, once for stroke).
     if (textMode & TextModeFill) {
         SkPaint paint;
         gc->platformContext()->setupPaintForFilling(&paint);
         setupPaint(&paint, font, this, shouldAntialias, shouldSmoothFonts);
         gc->platformContext()->adjustTextRenderMode(&paint);
         paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
 
-        platformContext->drawPosText(glyphs, numGlyphs * sizeof(uint16_t), pos, paint);
+        platformContext->drawPosText(glyphs, numGlyphs * sizeof(uint16_t), pos, textRect, paint);
     }
 
     if ((textMode & TextModeStroke)
         && gc->platformContext()->getStrokeStyle() != NoStroke
         && gc->platformContext()->getStrokeThickness() > 0) {
 
         SkPaint paint;
         gc->platformContext()->setupPaintForStroking(&paint, 0, 0);
         setupPaint(&paint, font, this, shouldAntialias, shouldSmoothFonts);
         gc->platformContext()->adjustTextRenderMode(&paint);
         paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
 
         if (textMode & TextModeFill) {
             // If we also filled, we don't want to draw shadows twice.
             // See comment in FontChromiumWin.cpp::paintSkiaText() for more details.
             paint.setLooper(0);
         }
 
-        platformContext->drawPosText(glyphs, numGlyphs * sizeof(uint16_t), pos, paint);
+        platformContext->drawPosText(glyphs, numGlyphs * sizeof(uint16_t), pos, textRect, paint);
     }
     if (font->platformData().orientation() == Vertical)
         platformContext->restore();
 }
 
 } // namespace WebCore