RenderText: Fix crash itemizing obscured emoji.

ui/gfx/render_text_harfbuzz.cc

Index: ui/gfx/render_text_harfbuzz.cc
diff --git a/ui/gfx/render_text_harfbuzz.cc b/ui/gfx/render_text_harfbuzz.cc
index dac89b9bbd4b8f31217814f82a6f27c5e00adcad..b2002af89400534a4427b431ab7afd9f4c78dd51 100644
--- a/ui/gfx/render_text_harfbuzz.cc
+++ b/ui/gfx/render_text_harfbuzz.cc
@@ -1271,7 +1271,7 @@ void RenderTextHarfBuzz::ItemizeTextToRuns(
   // Build the run list from the script items and ranged styles and baselines.
   // Use an empty color BreakList to avoid breaking runs at color boundaries.
   BreakList<SkColor> empty_colors;
-  empty_colors.SetMax(text.length());
+  empty_colors.SetMax(colors().max());
   DCHECK_LE(text.size(), baselines().max());
   for (const BreakList<bool>& style : styles())
     DCHECK_LE(text.size(), style.max());