impl(spanner): remove deprecated ClientOptions

doc/v3-migration-guide.md

@@ -263,6 +263,48 @@ guide:
 ### Spanner
 
 <details>
+<summary>Removed <code>spanner::ClientOptions</code> class</summary>
+
+The `spanner::ClientOptions` class has been removed. Use
+`google::cloud::Options` instead to set the following as needed:
+
+- `spanner::QueryOptimizerVersionOption`
+- `spanner::QueryOptimizerStatisticsPackageOption`
+- `spanner::RequestPriorityOption`
+- `spanner::RequestTagOption`
+
+**Before:**
+
+```cpp
+#include "google/cloud/spanner/client.h"
+
+// ...
+
+namespace spanner = ::google::cloud::spanner;
+auto client_options = spanner::ClientOptions().set_query_options(
+    spanner::QueryOptions().set_optimizer_version("1"));
+
+auto client = spanner::Client(connection, client_options);
+```
+
+**After:**
+
+```cpp
+#include "google/cloud/spanner/client.h"
+#include "google/cloud/spanner/options.h"
+
+// ...
+
+namespace spanner = ::google::cloud::spanner;
+auto options = google::cloud::Options{}.set<spanner::QueryOptimizerVersionOption>("1");
+
+auto client = spanner::Client(connection, options);
+```
+
+</details>
+
+<details>
+
 <summary>Removed <code>admin/retry_traits.h</code> file</summary>
 
 The library no longer exposes `google/cloud/spanner/admin/retry_traits.h` header

google/cloud/spanner/CMakeLists.txt

@@ -96,7 +96,6 @@ add_library(
     bytes.h
     client.cc
     client.h
-    client_options.h
     commit_options.cc
     commit_options.h
     commit_result.h
@@ -455,7 +454,6 @@ function (spanner_client_define_tests)
         # cmake-format: sort
         backup_test.cc
         bytes_test.cc
-        client_options_test.cc
         client_test.cc
         commit_options_test.cc
         connection_options_test.cc

google/cloud/spanner/client.h

@@ -16,7 +16,6 @@
 #define GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_SPANNER_CLIENT_H
 
 #include "google/cloud/spanner/batch_dml_result.h"
-#include "google/cloud/spanner/client_options.h"
 #include "google/cloud/spanner/commit_options.h"
 #include "google/cloud/spanner/commit_result.h"
 #include "google/cloud/spanner/connection.h"
@@ -717,15 +716,6 @@ class Client {
   StatusOr<PartitionedDmlResult> ExecutePartitionedDml(SqlStatement statement,
                                                        Options opts = {});
 
-  ///@{
-  /// @name Backwards compatibility for ClientOptions.
-  explicit Client(std::shared_ptr<Connection> conn, ClientOptions const& opts)
-      : Client(std::move(conn), Options(opts)) {}
-  explicit Client(std::shared_ptr<Connection> conn,
-                  std::initializer_list<internal::NonConstructible>)
-      : Client(std::move(conn)) {}
-  ///@}
-
   ///@{
   /// @name Backwards compatibility for ReadOptions.
   /**

google/cloud/spanner/client_test.cc

@@ -1313,26 +1313,6 @@ TEST(ClientTest, UsesConnectionOptions) {
   EXPECT_STATUS_OK(rollback);
 }
 
-TEST(ClientTest, UsesClientOptions) {
-  auto conn = std::make_shared<MockConnection>();
-  auto txn = MakeReadWriteTransaction();
-
-  EXPECT_CALL(*conn, options).WillOnce([] {
-    return Options{}.set<StringOption>("connection");
-  });
-  EXPECT_CALL(*conn, Rollback)
-      .WillOnce([txn](Connection::RollbackParams const& params) {
-        auto const& options = internal::CurrentOptions();
-        EXPECT_THAT(options.get<StringOption>(), Eq("client"));
-        EXPECT_THAT(params.transaction, Eq(txn));
-        return Status();
-      });
-
-  Client client(conn, Options{}.set<StringOption>("client"));
-  auto rollback = client.Rollback(txn, Options{});
-  EXPECT_STATUS_OK(rollback);
-}
-
 TEST(ClientTest, UsesOperationOptions) {
   auto conn = std::make_shared<MockConnection>();
   auto txn = MakeReadWriteTransaction();

google/cloud/spanner/google_cloud_cpp_spanner.bzl

@@ -50,7 +50,6 @@ google_cloud_cpp_spanner_hdrs = [
     "batch_dml_result.h",
     "bytes.h",
     "client.h",
-    "client_options.h",
     "commit_options.h",
     "commit_result.h",
     "connection.h",

google/cloud/spanner/spanner_client_unit_tests.bzl

@@ -19,7 +19,6 @@
 spanner_client_unit_tests = [
     "backup_test.cc",
     "bytes_test.cc",
-    "client_options_test.cc",
     "client_test.cc",
     "commit_options_test.cc",
     "connection_options_test.cc",