Use font linking based on the original run font in RenderTextWin.

ui/gfx/render_text_win.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_win.h"
 
 #include <algorithm>
 
 #include "base/i18n/break_iterator.h"
 #include "base/logging.h"
@@ skipping 579 matching lines @@
 
   HRESULT hr = E_FAIL;
   string_size_.set_height(0);
   for (size_t i = 0; i < runs_.size(); ++i) {
     internal::TextRun* run = runs_[i];
     size_t run_length = run->range.length();
     const wchar_t* run_text = &(text()[run->range.start()]);
     bool tried_fallback = false;
     size_t linked_font_index = 0;
     const std::vector<Font>* linked_fonts = NULL;
+    Font original_font = run->font;
 
     // Select the font desired for glyph generation.
     SelectObject(cached_hdc_, run->font.GetNativeFont());
 
     SCRIPT_FONTPROPERTIES properties;
     memset(&properties, 0, sizeof(properties));
     properties.cBytes = sizeof(properties);
 
     run->logical_clusters.reset(new WORD[run_length]);
     run->glyph_count = 0;
@@ skipping 44 matching lines @@
         Font fallback_font;
         if (ChooseFallbackFont(cached_hdc_, run->font, run_text, run_length,
                                &fallback_font)) {
           ApplySubstituteFont(run, fallback_font);
           continue;
         }
       }
 
       // The meta file approach did not yield a replacement font, try to find
       // one using font linking. First time through, get the linked fonts list.
-      if (linked_fonts == NULL)
-        linked_fonts = GetLinkedFonts(run->font);
+      if (linked_fonts == NULL) {
+        // First, try to get the list for the original font.
+        linked_fonts = GetLinkedFonts(original_font);
+
+        // If there are no linked fonts for the original font, try querying the
+        // ones for the Uniscribe fallback font. This may happen if the first
+        // font is a custom font that has no linked fonts in the Registry.
+        //
+        // Note: One possibility would be to always merge both lists of fonts,
+        //       but it is not clear whether there are any real world scenarios
+        //       where this would actually help.
+        if (linked_fonts->empty())
+          linked_fonts = GetLinkedFonts(run->font);
+      }
 
       // None of the linked fonts worked, break out of the loop.
       if (linked_font_index == linked_fonts->size()) {
         // TODO(msw): Don't use SCRIPT_UNDEFINED. Apparently Uniscribe can
         //            crash on certain surrogate pairs with SCRIPT_UNDEFINED.
         //            See https://bugzilla.mozilla.org/show_bug.cgi?id=341500
         //            And http://maxradi.us/documents/uniscribe/
         run->script_analysis.eScript = SCRIPT_UNDEFINED;
         // Reset |hr| to 0 to not trigger the DCHECK() below when a font is
         // not found that can display the text. This is expected behavior
@@ skipping 108 matching lines @@
     internal::TextRun* run) {
   size_t caret = IndexOfAdjacentGrapheme(run->range.end(), CURSOR_BACKWARD);
   return SelectionModel(caret, CURSOR_FORWARD);
 }
 
 RenderText* RenderText::CreateRenderText() {
   return new RenderTextWin;
 }
 
 }  // namespace gfx