Make the UI font honor the OS settings when the resource bundle is not available.

app/l10n_util_win.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/l10n_util.h"
 #include "app/l10n_util_win.h"
 
 #include <algorithm>
 #include <windowsx.h>
 
@@ skipping 69 matching lines @@
   // we need separate ui font specifications.
   int ui_font_family_id = IDS_UI_FONT_FAMILY;
   int ui_font_size_scaler_id = IDS_UI_FONT_SIZE_SCALER;
   if (win_util::GetWinVersion() < win_util::WINVERSION_VISTA) {
     ui_font_family_id = IDS_UI_FONT_FAMILY_XP;
     ui_font_size_scaler_id = IDS_UI_FONT_SIZE_SCALER_XP;
   }
 
   std::wstring ui_font_family = GetString(ui_font_family_id);
   int scaler100 = StringToInt(l10n_util::GetString(ui_font_size_scaler_id));
-  if (ui_font_family == L"default" && scaler100 == 100)
+  // We use the OS default in two cases:
+  // 1) The resource bundle has 'default' and '100' for font family and
+  //    font scaler.
+  // 2) The resource bundle is not available for some reason and 
+  //    ui_font_family is empty.
+  if (ui_font_family == L"default" && scaler100 == 100 ||
+      ui_font_family.empty())
     return false;
   if (override_font_family && font_size_scaler) {
     override_font_family->swap(ui_font_family);
     *font_size_scaler = scaler100 / 100.0;
   }
   return true;
 }
 
 void AdjustUIFont(LOGFONT* logfont) {
   std::wstring ui_font_family;
@@ skipping 10 matching lines @@
     if (GetObject(GetWindowFont(hwnd), sizeof(logfont), &logfont)) {
       AdjustLogFont(ui_font_family, ui_font_size_scaler, &logfont);
       HFONT hfont = CreateFontIndirect(&logfont);
       if (hfont)
         SetWindowFont(hwnd, hfont, FALSE);
     }
   }
 }
 
 }  // namespace l10n_util