[Omnibox] Elide omnibox 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 <set>
 
 #include "base/i18n/bidi_line_iterator.h"
@@ skipping 1162 matching lines @@
 }
 
 void RenderTextHarfBuzz::OnLayoutTextAttributeChanged(bool text_changed) {
   update_layout_run_list_ = true;
   OnDisplayTextAttributeChanged();
 }
 
 void RenderTextHarfBuzz::OnDisplayTextAttributeChanged() {
   update_display_text_ = true;
   update_grapheme_iterator_ = true;
+  std::vector<internal::Line> empty_lines;
+  set_lines(&empty_lines);
 }
 
 void RenderTextHarfBuzz::EnsureLayout() {
   EnsureLayoutRunList();
 
   if (update_display_run_list_) {
     DCHECK(text_elided());
     const base::string16& display_text = GetDisplayText();
     display_run_list_.reset(new internal::TextRunList);
 
@@ skipping 449 matching lines @@
       ItemizeTextToRuns(text, &layout_run_list_);
 
       // TODO(ckocagil): Remove ScopedTracker below once crbug.com/441028 is
       // fixed.
       tracked_objects::ScopedTracker tracking_profile(
           FROM_HERE_WITH_EXPLICIT_FUNCTION("441028 ShapeRunList() 2"));
       ShapeRunList(text, &layout_run_list_);
     }
 
     std::vector<internal::Line> empty_lines;
     set_lines(&empty_lines);

[msw, 2017/04/17 23:51:44]

Instead of adding a similar operation in
RenderTextHarfBuzz::OnDisplayTextAttributeChanged, can you move this set_lines()
call to the top of the |if (update_display_text_)| block below? That should
clear |lines_| anytime the layout or display text needs an update.

[simonhong, 2017/04/18 13:33:33]

Yes, it's much better place.
Done.

     display_run_list_.reset();
     update_display_text_ = true;
     update_layout_run_list_ = false;
   }
   if (update_display_text_) {
     UpdateDisplayText(multiline() ? 0 : layout_run_list_.width());
     update_display_text_ = false;
     update_display_run_list_ = text_elided();
   }
 }
@@ skipping 41 matching lines @@
 
       attribute.strike = run.strike;
       attribute.diagonal_strike = run.diagonal_strike;
       decorated_text->attributes.push_back(attribute);
     }
   }
   return true;
 }
 
 }  // namespace gfx