Got the about panel to have its text lined up correctly.

app/gfx/canvas_linux.cc

 // Copyright (c) 2009 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 "app/gfx/canvas.h"
 
 #include <cairo/cairo.h>
 #include <gtk/gtk.h>
 #include <pango/pango.h>
 #include <pango/pangocairo.h>
@@ skipping 167 matching lines @@
                        SkColorGetR(color) / 255.0,
                        SkColorGetG(color) / 255.0,
                        SkColorGetB(color) / 255.0);
 
   std::string utf8 = WideToUTF8(text);
   pango_layout_set_text(layout, utf8.data(), utf8.size());
 
   int width, height;
   pango_layout_get_pixel_size(layout, &width, &height);
 
+  cairo_rectangle(cr, x, y, width, height);
+  cairo_clip(cr);
+
   if (flags & Canvas::TEXT_VALIGN_TOP) {
     // Cairo should draw from the top left corner already.
   } else if (flags & Canvas::TEXT_VALIGN_BOTTOM) {
     y += (h - height);
   } else {
     // Vertically centered.
     y += ((h - height) / 2);
   }
 
-  cairo_rectangle(cr, x, y, w, h);
-  cairo_clip(cr);
-
   cairo_move_to(cr, x, y);
   pango_cairo_show_layout(cr, layout);
+  if (font.style() & gfx::Font::UNDERLINED) {
+    double underline_y =
+        static_cast<double>(y) + height + font.underline_position();
+    cairo_set_line_width(cr, font.underline_thickness());
+    cairo_move_to(cr, x, underline_y);
+    cairo_line_to(cr, x + width, underline_y);
+    cairo_stroke(cr);
+  }
   cairo_restore(cr);
 
   g_object_unref(layout);
   // NOTE: beginPlatformPaint returned its surface, we shouldn't destroy it.
 }
 
 void Canvas::DrawGdkPixbuf(GdkPixbuf* pixbuf, int x, int y) {
   if (!pixbuf) {
     NOTREACHED();
     return;
   }
 
   cairo_t* cr = beginPlatformPaint();
   gdk_cairo_set_source_pixbuf(cr, pixbuf, x, y);
   cairo_paint(cr);
 }
 
 }  // namespace gfx