Add RenderText DirectionalityMode enum and support; etc.

ui/gfx/pango_util.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/pango_util.h"
 
 #include <cairo/cairo.h>
 #include <fontconfig/fontconfig.h>
 #include <pango/pango.h>
 #include <pango/pangocairo.h>
@@ skipping 186 matching lines @@
   // This needs to be done early on; it has no effect when called just before
   // pango_cairo_show_layout().
   pango_cairo_context_set_font_options(
       pango_layout_get_context(layout), cairo_font_options);
 
   if (copied_cairo_font_options) {
     cairo_font_options_destroy(cairo_font_options);
     cairo_font_options = NULL;
   }
 
-  // Callers of DrawStringInt handle RTL layout themselves, so tell pango to not
-  // scope out RTL characters.
+  // Set Pango's base text direction explicitly from |text_direction|.
   pango_layout_set_auto_dir(layout, FALSE);
+  pango_context_set_base_dir(pango_layout_get_context(layout),
+      (text_direction == base::i18n::RIGHT_TO_LEFT ?
+       PANGO_DIRECTION_RTL : PANGO_DIRECTION_LTR));
 
   if (width > 0)
     pango_layout_set_width(layout, width * PANGO_SCALE);
 
   if (flags & Canvas::TEXT_ALIGN_CENTER) {
     // We don't support center aligned w/ eliding.
     DCHECK(gfx::Canvas::NO_ELLIPSIS);
     pango_layout_set_alignment(layout, PANGO_ALIGN_CENTER);
   } else if (flags & Canvas::TEXT_ALIGN_RIGHT) {
     pango_layout_set_alignment(layout, PANGO_ALIGN_RIGHT);
@@ skipping 202 matching lines @@
 
   if (i == desc_to_metrics->end()) {
     PangoFontMetrics* metrics = pango_context_get_metrics(context, desc, NULL);
     desc_to_metrics->insert(std::make_pair(desc_hash, metrics));
     return metrics;
   }
   return i->second;
 }
 
 }  // namespace gfx