Track the region where text is painted.

Source/core/platform/graphics/chromium/UniscribeHelper.h

 /*
  * Copyright (c) 2006, 2007, 2008, 2009, 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 26 matching lines @@
 #include <usp10.h>
 #include <map>
 
 #include <unicode/uchar.h>
 #include <wtf/Vector.h>
 
 class UniscribeTest_TooBig_Test; // A gunit test for UniscribeHelper.
 
 namespace WebCore {
 
+class FloatRect;
 class FontFeatureSettings;
 class GraphicsContext;
 
 const unsigned cUniscribeHelperStackRuns = 8;
 const unsigned cUniscribeHelperStackChars = 32;
 const unsigned cUniscribeHelperFeatures = 4;
 
 // This object should be safe to create & destroy frequently, as long as the
 // caller preserves the script_cache when possible (this data may be slow to
 // compute).
@@ skipping 132 matching lines @@
     // Converts the given pixel X position into a logical character offset into
     // the run. For positions appearing before the first character, this will
     // return -1.
     int xToCharacter(int x) const;
 
     // Draws the given characters to (x, y) in the given DC. The font will be
     // handled by this function, but the font color and other attributes should
     // be pre-set.
     //
     // The y position is the upper left corner, NOT the baseline.
-    void draw(GraphicsContext* graphicsContext, HDC dc, int x, int y, int from,
-              int to);
+    void draw(GraphicsContext* graphicsContext, HDC dc,
+              int x, int y,
+              const FloatRect& textRect,
+              int from, int to);
 
     // Returns the first glyph assigned to the character at the given offset.
     // This function is used to retrieve glyph information when Uniscribe is
     // being used to generate glyphs for non-complex, non-BMP (above U+FFFF)
     // characters. These characters are not otherwise special and have no
     // complex shaping rules, so we don't otherwise need Uniscribe, except
     // Uniscribe is the only way to get glyphs for non-BMP characters.
     //
     // Returns 0 if there is no glyph for the given character.
     WORD firstGlyphForCharacter(int charOffset) const;
@@ skipping 221 matching lines @@
 
     // This contains Uniscribe's OpenType feature settings. This structure
     // is filled by using WebKit's |FontFeatureSettings|.
     TEXTRANGE_PROPERTIES m_rangeProperties;
     Vector<OPENTYPE_FEATURE_RECORD, cUniscribeHelperFeatures> m_featureRecords;
 };
 
 }  // namespace WebCore
 
 #endif  // UniscribeHelper_h