Cleanup namespace ending comment

(This is a merge of http://go/wvgerrit/13400 from the Widevine CDM
repository.)

Replace "};  // namespace" with "}  // namespace":
ag -l --ignore-dir third_party "};  //" | \
while read f; do sed -r -i 's/\};  \/\//}  \/\//' $f ; done

Replace "// unnamed namespace" with "// namespace":
ag -l --ignore-dir third_party "unnamed namespace" | \
while read f; do sed -r -i 's/unnamed namespace/namespace/' $f ; done

Change-Id: I50ece9a127ce669f15cd532dfae1dd741338a075

libwvdrmengine/cdm/core/test/test_printers.cpp

@@ -90,4 +90,4 @@ void PrintTo(const enum CdmCertificateType& value, ::std::ostream* os) {
   }
 };
 
-};  // namespace wvcdm
+}  // namespace wvcdm