Fix accidental updates of host's baselines_ in Elide().

ui/gfx/render_text_harfbuzz.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/render_text_harfbuzz.h"
 
 #include <limits>
 #include <set>
 
 #include "base/i18n/bidi_line_iterator.h"
@@ skipping 1146 matching lines @@
     return;
   }
 
   // Temporarily apply composition underlines and selection colors.
   ApplyCompositionAndSelectionStyles();
 
   // 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());
+  DCHECK_LE(text.size(), baselines().max());
+  for (const BreakList<bool>& style : styles())
+    DCHECK_LE(text.size(), style.max());
   internal::StyleIterator style(empty_colors, baselines(), styles());
 
   for (size_t run_break = 0; run_break < text.length();) {
     internal::TextRunHarfBuzz* run = new internal::TextRunHarfBuzz;
     run->range.set_start(run_break);
     run->font_style = (style.style(BOLD) ? Font::BOLD : 0) |
                       (style.style(ITALIC) ? Font::ITALIC : 0);
     run->baseline_type = style.baseline();
     run->strike = style.style(STRIKE);
     run->diagonal_strike = style.style(DIAGONAL_STRIKE);
@@ skipping 348 matching lines @@
   DCHECK(!update_layout_run_list_);
   DCHECK(!update_display_run_list_);
   return text_elided() ? display_run_list_.get() : &layout_run_list_;
 }
 
 const internal::TextRunList* RenderTextHarfBuzz::GetRunList() const {
   return const_cast<RenderTextHarfBuzz*>(this)->GetRunList();
 }
 
 }  // namespace gfx