Use ChildThreadImpl::thread_safe_sender in font proxy if available

content/child/dwrite_font_proxy/font_fallback_win_unittest.cc

Index: content/child/dwrite_font_proxy/font_fallback_win_unittest.cc
diff --git a/content/child/dwrite_font_proxy/font_fallback_win_unittest.cc b/content/child/dwrite_font_proxy/font_fallback_win_unittest.cc
index b5faca2bcc0128949cf4cf549b6f1e95ba20ef01..90d82c44ead3617cf34ba53646499dbe9c85bf40 100644
--- a/content/child/dwrite_font_proxy/font_fallback_win_unittest.cc
+++ b/content/child/dwrite_font_proxy/font_fallback_win_unittest.cc
@@ -44,7 +44,8 @@ class FontFallbackUnitTest : public testing::Test {
         .AddFilePath(segoe_path);
 
     mswr::MakeAndInitialize<DWriteFontCollectionProxy>(
-        &collection_, factory_.Get(), fake_collection_->GetSender());
+        &collection_, factory_.Get(),
+        base::Bind(&FakeFontCollection::GetSender, fake_collection_));
   }
 
   void CreateDWriteFactory(IUnknown** factory) {