Fix the x-offset calculation when drawing the text.

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 "base/i18n/bidi_line_iterator.h"
 #include "base/i18n/break_iterator.h"
@@ skipping 994 matching lines @@
     const Vector2d origin = GetLineOffset(i) + Vector2d(0, line.baseline);
     SkScalar preceding_segment_widths = 0;
     for (const internal::LineSegment& segment : line.segments) {
       const internal::TextRunHarfBuzz& run = *run_list->runs()[segment.run];
       renderer.SetTypeface(run.skia_face.get());
       renderer.SetTextSize(SkIntToScalar(run.font_size));
       renderer.SetFontRenderParams(run.render_params,
                                    background_is_transparent());
       Range glyphs_range = run.CharRangeToGlyphRange(segment.char_range);
       scoped_ptr<SkPoint[]> positions(new SkPoint[glyphs_range.length()]);
-      SkScalar offset_x =
-          preceding_segment_widths - run.positions[glyphs_range.start()].x();
+      SkScalar offset_x = preceding_segment_widths -
+                          ((glyphs_range.GetMin() != 0)
+                               ? run.positions[glyphs_range.GetMin()].x()
+                               : 0);
       for (size_t j = 0; j < glyphs_range.length(); ++j) {
         positions[j] = run.positions[(glyphs_range.is_reversed()) ?
                                      (glyphs_range.start() - j) :
                                      (glyphs_range.start() + j)];
         positions[j].offset(SkIntToScalar(origin.x()) + offset_x,
                             SkIntToScalar(origin.y()));
       }
       for (BreakList<SkColor>::const_iterator it =
                colors().GetBreak(segment.char_range.start());
            it != colors().breaks().end() &&
@@ skipping 430 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