Update SVG text layout to use shaped glyph data & go fast (O(n^2)->O(n))

third_party/WebKit/Source/platform/fonts/shaping/CachingWordShaper.cpp

 /*
  * Copyright (C) 2015 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 98 matching lines @@
 CharacterRange CachingWordShaper::getCharacterRange(const Font* font,
     const TextRun& run, unsigned from, unsigned to)
 {
     ShapeResultBuffer buffer;
     float totalWidth = shapeResultsForRun(m_shapeCache, font, run, nullptr,
         &buffer);
 
     return buffer.getCharacterRange(run.direction(), totalWidth, from, to);
 }
 
+Vector<CharacterRange> CachingWordShaper::individualCharacterRanges(
+    const Font* font, const TextRun& run, unsigned from, unsigned to)
+{
+    ShapeResultBuffer buffer;
+    float totalWidth = shapeResultsForRun(m_shapeCache, font, run, nullptr,
+        &buffer);
+
+    Vector<CharacterRange> allExtents;
+    for (unsigned position = from; position <= to; position++) {
+        allExtents.append(buffer.getCharacterRange(run.direction(), totalWidth,
+            position, position + 1));
+    }
+
+    return allExtents;
+}
+
 }; // namespace blink