Track the region where text is painted.

Source/core/platform/graphics/GraphicsContext.cpp

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2013 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 853 matching lines @@
     if (paintingDisabled())
         return;
 
     ASSERT(!rect.isEmpty());
     if (rect.isEmpty())
         return;
 
     platformContext()->drawRect(rect);
 }
 
-void GraphicsContext::drawText(const Font& font, const TextRun& run, const FloatPoint& point, int from, int to)
+void GraphicsContext::drawText(const Font& font, const TextRunPaintInfo& runInfo, const FloatPoint& point)
 {
     if (paintingDisabled())
         return;
 
-    font.drawText(this, run, point, from, to);
+    font.drawText(this, runInfo, point);
 }
 
-void GraphicsContext::drawEmphasisMarks(const Font& font, const TextRun& run, const AtomicString& mark, const FloatPoint& point, int from, int to)
+void GraphicsContext::drawEmphasisMarks(const Font& font, const TextRunPaintInfo& runInfo, const AtomicString& mark, const FloatPoint& point)
 {
     if (paintingDisabled())
         return;
 
-    font.drawEmphasisMarks(this, run, mark, point, from, to);
+    font.drawEmphasisMarks(this, runInfo, mark, point);
 }
 
-void GraphicsContext::drawBidiText(const Font& font, const TextRun& run, const FloatPoint& point, Font::CustomFontNotReadyAction customFontNotReadyAction)
+void GraphicsContext::drawBidiText(const Font& font, const TextRunPaintInfo& runInfo, const FloatPoint& point, Font::CustomFontNotReadyAction customFontNotReadyAction)
 {
     if (paintingDisabled())
         return;
 
+    // sub-run painting is not supported for Bidi text.
+    const TextRun& run = runInfo.run;
+    ASSERT((runInfo.from == 0) && (runInfo.to == run.length()));
     BidiResolver<TextRunIterator, BidiCharacterRun> bidiResolver;
     bidiResolver.setStatus(BidiStatus(run.direction(), run.directionalOverride()));
     bidiResolver.setPositionIgnoringNestedIsolates(TextRunIterator(&run, 0));
 
     // FIXME: This ownership should be reversed. We should pass BidiRunList
     // to BidiResolver in createBidiRunsForLine.
     BidiRunList<BidiCharacterRun>& bidiRuns = bidiResolver.runs();
     bidiResolver.createBidiRunsForLine(TextRunIterator(&run, run.length()));
     if (!bidiRuns.runCount())
         return;
 
     FloatPoint currPoint = point;
     BidiCharacterRun* bidiRun = bidiRuns.firstRun();
     while (bidiRun) {
         TextRun subrun = run.subRun(bidiRun->start(), bidiRun->stop() - bidiRun->start());
         bool isRTL = bidiRun->level() % 2;
         subrun.setDirection(isRTL ? RTL : LTR);
         subrun.setDirectionalOverride(bidiRun->dirOverride(false));
 
-        font.drawText(this, subrun, currPoint, 0, -1, customFontNotReadyAction);
+        TextRunPaintInfo subrunInfo(subrun);
+        subrunInfo.bounds = runInfo.bounds;
+        font.drawText(this, subrunInfo, currPoint, customFontNotReadyAction);
 
         bidiRun = bidiRun->next();
         // FIXME: Have Font::drawText return the width of what it drew so that we don't have to re-measure here.
         if (bidiRun)
             currPoint.move(font.width(subrun), 0);
     }
 
     bidiRuns.deleteRuns();
 }
 
@@ skipping 838 matching lines @@
     static const SkPMColor colors[] = {
         SkPreMultiplyARGB(0x60, 0xFF, 0x00, 0x00), // More transparent red
         SkPreMultiplyARGB(0x60, 0xC0, 0xC0, 0xC0)  // More transparent gray
     };
 
     return colors[index];
 }
 #endif
 
 }