[vr] Fix incorrect negation in font fallback logic.

chrome/browser/android/vr_shell/textures/ui_texture.cc

 // Copyright 2017 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 "chrome/browser/android/vr_shell/textures/ui_texture.h"
 
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 175 matching lines @@
   gfx::Font default_font(kDefaultFontFamily, size);
   std::vector<gfx::Font> fonts{default_font};
 
   std::set<std::string> names;
   // TODO(acondor): Query BrowserProcess to obtain the application locale.
   for (UChar32 c : CollectDifferentChars(text)) {
     std::string name;
     bool found_name = GetFallbackFontNameForChar(default_font, c, "", &name);
     if (!found_name)
       return false;
-    if (name.empty())
+    if (!name.empty())
       names.insert(name);
   }
-  for (const auto& name : names)
+  for (const auto& name : names) {
+    DCHECK(!name.empty());
     fonts.push_back(gfx::Font(name, size));
+  }
   *font_list = gfx::FontList(fonts);
   return true;
 }
 
 void UiTexture::SetForceFontFallbackFailureForTesting(bool force) {
   force_font_fallback_failure_for_testing_ = force;
 }
 
 }  // namespace vr_shell