minidump: Use the crashpad::internal namespace more appropriately

minidump/minidump_string_writer_test.cc

Index: minidump/minidump_string_writer_test.cc
diff --git a/minidump/minidump_string_writer_test.cc b/minidump/minidump_string_writer_test.cc
index 8854f444f8334e3604efa52c0a496d4ade51435a..ab09b6e66835686cade0502b578a033dc7964b75 100644
--- a/minidump/minidump_string_writer_test.cc
+++ b/minidump/minidump_string_writer_test.cc
@@ -198,7 +198,7 @@ TEST(MinidumpStringWriter, MinidumpUTF8StringWriter) {
 }
 
 struct MinidumpUTF16StringListWriterTraits {
-  using MinidumpStringListWriterType = internal::MinidumpUTF16StringListWriter;
+  using MinidumpStringListWriterType = MinidumpUTF16StringListWriter;
   static string16 ExpectationForUTF8(const std::string& utf8) {
     return base::UTF8ToUTF16(utf8);
   }
@@ -208,7 +208,7 @@ struct MinidumpUTF16StringListWriterTraits {
 };
 
 struct MinidumpUTF8StringListWriterTraits {
-  using MinidumpStringListWriterType = internal::MinidumpUTF8StringListWriter;
+  using MinidumpStringListWriterType = MinidumpUTF8StringListWriter;
   static std::string ExpectationForUTF8(const std::string& utf8) {
     return utf8;
   }