Move gfx::ElideText functionality to RenderText.

ui/gfx/render_text_pango.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_pango.h"
 
 #include <pango/pangocairo.h>
 #include <algorithm>
 #include <string>
 #include <vector>
@@ skipping 64 matching lines @@
 }
 
 RenderTextPango::~RenderTextPango() {
   ResetLayout();
 }
 
 Size RenderTextPango::GetStringSize() {
   EnsureLayout();
   int width = 0, height = 0;
   pango_layout_get_pixel_size(layout_, &width, &height);
+
+  // Pango returns 0 widths for very long strings (of 0x40000 chars or more).
+  // This is caused by an int overflow in pango_glyph_string_extents_range.
+  // Absurdly long strings may even report non-zero garbage values for width;
+  // while detecting that isn't worthwhile, this handles the 0 width cases.

[Alexei Svitkine (slow), 2014/07/03 20:12:33]

Did we file a bug against pango for this? iirc Behdad is a maintainer of Pango,
so he may be able to fix this (we can still have the workaround here, just
better to fix the Pango bug too for the future).

Is this already covered by a test? If not, please add one.

[msw, 2014/07/08 19:07:36]

I'm not sure and can't find any relevant open bugs:
https://bugzilla.gnome.org/buglist.cgi?quicksearch=pango_layout_get_pixel_size
https://bugzilla.gnome.org/buglist.cgi?quicksearch=pango_glyph_string_extents...
+CC estade per http://crrev.com/32572 for http://crbug.com/15435
+CC Behdad for help finding or filing a bug.
Done; added RenderTextTest.StringSizeLongStrings.

[Evan Stade, 2014/07/08 21:07:19]

Unfortunately, my memory lasts exactly 5 years, so I've forgotten if I filed a
bug :)

I think the answer is "no".

+  const long kAbsurdLength = 100000;
+  if (width == 0 && g_utf8_strlen(layout_text_, -1) > kAbsurdLength)
+    width = font_list().GetExpectedTextWidth(g_utf8_strlen(layout_text_, -1));
+
   // Keep a consistent height between this particular string's PangoLayout and
   // potentially larger text supported by the FontList.
   // For example, if a text field contains a Japanese character, which is
   // smaller than Latin ones, and then later a Latin one is inserted, this
   // ensures that the text baseline does not shift.
   return Size(width, std::max(height, font_list().GetHeight()));
 }
 
 SelectionModel RenderTextPango::FindCursorPosition(const Point& point) {
   EnsureLayout();
@@ skipping 424 matching lines @@
                                           int glyph_index) const {
   return LayoutIndexToTextIndex(run->item->offset +
                                 run->glyphs->log_clusters[glyph_index]);
 }
 
 RenderText* RenderText::CreateNativeInstance() {
   return new RenderTextPango;
 }
 
 }  // namespace gfx