Don't reset the layout on RenderText display rect width change.

ui/gfx/render_text_linux.cc

 // Copyright (c) 2012 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_linux.h"
 
 #include <pango/pangocairo.h>
 #include <algorithm>
 #include <string>
 #include <vector>
@@ skipping 265 matching lines @@
         cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 0, 0);
     cairo_t* cr = cairo_create(surface);
 
     layout_ = pango_cairo_create_layout(cr);
     cairo_destroy(cr);
     cairo_surface_destroy(surface);
 
     SetupPangoLayoutWithFontDescription(layout_,
                                         GetDisplayText(),
                                         font_list().GetFontDescriptionString(),
-                                        display_rect().width(),
+                                        0,

[msw, 2012/08/09 19:54:50]

Why not continue to pass in the width here? It's apparently used to configure
wrapping/eliding in SetupPangoLayoutWithoutFont.

[Alexei Svitkine (slow), 2012/08/09 20:03:01]

See the pango_layout_set_width() call below that just sets it -1
unconditionally. Passing 0 to SetupPangoLayoutWithFontDescription() avoids it
calling pango_layout_set_width() unnecessarily.

Plus, it's less confusing since the current code suggests that width is used in
layout, whereas in reality it isn't (because of the line below).

                                         GetTextDirection(),
                                         Canvas::DefaultCanvasTextAlignment());
 
     // No width set so that the x-axis position is relative to the start of the
     // text. ToViewPoint and ToTextPoint take care of the position conversion
     // between text space and view spaces.
     pango_layout_set_width(layout_, -1);
     // TODO(xji): If RenderText will be used for displaying purpose, such as
     // label, we will need to remove the single-line-mode setting.
     pango_layout_set_single_paragraph_mode(layout_, true);
@@ skipping 243 matching lines @@
   if (selection_visual_bounds_.empty())
     selection_visual_bounds_ = CalculateSubstringBounds(selection());
   return selection_visual_bounds_;
 }
 
 RenderText* RenderText::CreateInstance() {
   return new RenderTextLinux;
 }
 
 }  // namespace gfx