clean up unused code

Author: mpeddada1

google/cloud/storage/client_options_test.cc

@@ -36,10 +36,7 @@ namespace cloud {
 namespace storage {
 GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
 
-using ::google::cloud::testing_util::IsOk;
 using ::google::cloud::testing_util::ScopedEnvironment;
-using ::testing::IsEmpty;
-using ::testing::Not;
 using ::testing::UnorderedElementsAre;
 
 namespace {

google/cloud/storage/client_test.cc

@@ -37,8 +37,6 @@ namespace {
 
 using ::google::cloud::storage::internal::ClientImplDetails;
 using ::google::cloud::storage::testing::canonical_errors::TransientError;
-using ::google::cloud::testing_util::IsOkAndHolds;
-using ::google::cloud::testing_util::MockBackoffPolicy;
 using ::google::cloud::testing_util::ScopedEnvironment;
 using ::testing::ElementsAre;
 using ::testing::NotNull;

google/cloud/storage/internal/async/rewriter_connection_impl.h

@@ -20,7 +20,6 @@
 #include "google/cloud/storage/options.h"
 #include "google/cloud/completion_queue.h"
 #include "google/cloud/future.h"
-#include "google/cloud/options.h"
 #include "google/cloud/status_or.h"
 #include "google/cloud/version.h"
 #include "google/storage/v2/storage.pb.h"

google/cloud/storage/internal/grpc/stub.h

@@ -15,8 +15,8 @@
 #ifndef GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_STORAGE_INTERNAL_GRPC_STUB_H
 #define GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_STORAGE_INTERNAL_GRPC_STUB_H
 
-#include "google/cloud/storage/client_options.h"
 #include "google/cloud/storage/internal/generic_stub.h"
+#include "google/cloud/storage/client_options.h"
 #include "google/cloud/storage/version.h"
 #include "google/cloud/background_threads.h"
 #include "google/cloud/internal/minimal_iam_credentials_stub.h"

google/cloud/storage/testing/client_unit_test.cc

@@ -21,7 +21,6 @@ namespace storage {
 namespace testing {
 
 using ::testing::Return;
-using ::testing::ReturnRef;
 
 ClientUnitTest::ClientUnitTest()
     : mock_(std::make_shared<testing::MockClient>()) {