Refactor end2end_test. Make the credentials a separate library.
diff --git a/Makefile b/Makefile
index 6c7febd..62e873d 100644
--- a/Makefile
+++ b/Makefile
@@ -3162,6 +3162,7 @@
     test/cpp/util/create_test_channel.cc \
     test/cpp/util/string_ref_helper.cc \
     test/cpp/util/subprocess.cc \
+    test/cpp/util/test_credentials_provider.cc \
 
 
 LIBGRPC++_TEST_UTIL_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(LIBGRPC++_TEST_UTIL_SRC))))
@@ -3212,6 +3213,7 @@
 $(OBJDIR)/$(CONFIG)/test/cpp/util/create_test_channel.o: $(GENDIR)/src/proto/grpc/testing/echo_messages.pb.cc $(GENDIR)/src/proto/grpc/testing/echo_messages.grpc.pb.cc $(GENDIR)/src/proto/grpc/testing/echo.pb.cc $(GENDIR)/src/proto/grpc/testing/echo.grpc.pb.cc $(GENDIR)/src/proto/grpc/testing/duplicate/echo_duplicate.pb.cc $(GENDIR)/src/proto/grpc/testing/duplicate/echo_duplicate.grpc.pb.cc
 $(OBJDIR)/$(CONFIG)/test/cpp/util/string_ref_helper.o: $(GENDIR)/src/proto/grpc/testing/echo_messages.pb.cc $(GENDIR)/src/proto/grpc/testing/echo_messages.grpc.pb.cc $(GENDIR)/src/proto/grpc/testing/echo.pb.cc $(GENDIR)/src/proto/grpc/testing/echo.grpc.pb.cc $(GENDIR)/src/proto/grpc/testing/duplicate/echo_duplicate.pb.cc $(GENDIR)/src/proto/grpc/testing/duplicate/echo_duplicate.grpc.pb.cc
 $(OBJDIR)/$(CONFIG)/test/cpp/util/subprocess.o: $(GENDIR)/src/proto/grpc/testing/echo_messages.pb.cc $(GENDIR)/src/proto/grpc/testing/echo_messages.grpc.pb.cc $(GENDIR)/src/proto/grpc/testing/echo.pb.cc $(GENDIR)/src/proto/grpc/testing/echo.grpc.pb.cc $(GENDIR)/src/proto/grpc/testing/duplicate/echo_duplicate.pb.cc $(GENDIR)/src/proto/grpc/testing/duplicate/echo_duplicate.grpc.pb.cc
+$(OBJDIR)/$(CONFIG)/test/cpp/util/test_credentials_provider.o: $(GENDIR)/src/proto/grpc/testing/echo_messages.pb.cc $(GENDIR)/src/proto/grpc/testing/echo_messages.grpc.pb.cc $(GENDIR)/src/proto/grpc/testing/echo.pb.cc $(GENDIR)/src/proto/grpc/testing/echo.grpc.pb.cc $(GENDIR)/src/proto/grpc/testing/duplicate/echo_duplicate.pb.cc $(GENDIR)/src/proto/grpc/testing/duplicate/echo_duplicate.grpc.pb.cc
 
 
 LIBGRPC++_UNSECURE_SRC = \
@@ -13015,6 +13017,7 @@
 test/cpp/util/string_ref_helper.cc: $(OPENSSL_DEP)
 test/cpp/util/subprocess.cc: $(OPENSSL_DEP)
 test/cpp/util/test_config.cc: $(OPENSSL_DEP)
+test/cpp/util/test_credentials_provider.cc: $(OPENSSL_DEP)
 endif
 
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