Put SkEmptyTypeface in anonymous namespace.

tests/TypefaceTest.cpp

Index: tests/TypefaceTest.cpp
diff --git a/tests/TypefaceTest.cpp b/tests/TypefaceTest.cpp
index 130cabf37a72562c96da12a545b47e02503800d6..950449d9c1837706abcd5d69287d8adaef8e8624 100644
--- a/tests/TypefaceTest.cpp
+++ b/tests/TypefaceTest.cpp
@@ -27,6 +27,8 @@ DEF_TEST(Typeface, reporter) {
 #endif
 }
 
+namespace {
+
 class SkEmptyTypeface : public SkTypeface {
 public:
     static sk_sp<SkTypeface> Create(SkFontID id) { return sk_sp<SkTypeface>(new SkEmptyTypeface(id)); }
@@ -59,6 +61,8 @@ protected:
     size_t onGetTableData(SkFontTableTag, size_t, size_t, void*) const override { return 0; }
 };
 
+}
+
 static bool count_proc(SkTypeface* face, void* ctx) {
     int* count = static_cast<int*>(ctx);
     *count = *count + 1;