Better layering support for grpc++.
diff --git a/BUILD b/BUILD
index 1ed55a6..6416cef 100644
--- a/BUILD
+++ b/BUILD
@@ -111,6 +111,103 @@
     ],
 )
 
+# TODO(ctiller): layer grpc atop grpc_unsecure, layer grpc++ atop grpc++_unsecure
+GRPCXX_SRCS = [
+    "src/cpp/client/channel_cc.cc",
+    "src/cpp/client/client_context.cc",
+    "src/cpp/client/create_channel.cc",
+    "src/cpp/client/create_channel_internal.cc",
+    "src/cpp/client/create_channel_posix.cc",
+    "src/cpp/client/credentials_cc.cc",
+    "src/cpp/client/generic_stub.cc",
+    "src/cpp/common/channel_arguments.cc",
+    "src/cpp/common/channel_filter.cc",
+    "src/cpp/common/completion_queue_cc.cc",
+    "src/cpp/common/core_codegen.cc",
+    "src/cpp/common/resource_quota_cc.cc",
+    "src/cpp/common/rpc_method.cc",
+    "src/cpp/common/version_cc.cc",
+    "src/cpp/server/async_generic_service.cc",
+    "src/cpp/server/channel_argument_option.cc",
+    "src/cpp/server/create_default_thread_pool.cc",
+    "src/cpp/server/dynamic_thread_pool.cc",
+    "src/cpp/server/health/default_health_check_service.cc",
+    "src/cpp/server/health/health.pb.c",
+    "src/cpp/server/health/health_check_service.cc",
+    "src/cpp/server/health/health_check_service_server_builder_option.cc",
+    "src/cpp/server/server_builder.cc",
+    "src/cpp/server/server_cc.cc",
+    "src/cpp/server/server_context.cc",
+    "src/cpp/server/server_credentials.cc",
+    "src/cpp/server/server_posix.cc",
+    "src/cpp/thread_manager/thread_manager.cc",
+    "src/cpp/util/byte_buffer_cc.cc",
+    "src/cpp/util/slice_cc.cc",
+    "src/cpp/util/status.cc",
+    "src/cpp/util/string_ref.cc",
+    "src/cpp/util/time_cc.cc",
+]
+
+GRPCXX_HDRS = [
+    "src/cpp/client/create_channel_internal.h",
+    "src/cpp/common/channel_filter.h",
+    "src/cpp/server/dynamic_thread_pool.h",
+    "src/cpp/server/health/default_health_check_service.h",
+    "src/cpp/server/health/health.pb.h",
+    "src/cpp/server/thread_pool_interface.h",
+    "src/cpp/thread_manager/thread_manager.h",
+]
+
+GRPCXX_PUBLIC_HDRS = [
+    "include/grpc++/alarm.h",
+    "include/grpc++/channel.h",
+    "include/grpc++/client_context.h",
+    "include/grpc++/completion_queue.h",
+    "include/grpc++/create_channel.h",
+    "include/grpc++/create_channel_posix.h",
+    "include/grpc++/ext/health_check_service_server_builder_option.h",
+    "include/grpc++/generic/async_generic_service.h",
+    "include/grpc++/generic/generic_stub.h",
+    "include/grpc++/grpc++.h",
+    "include/grpc++/health_check_service_interface.h",
+    "include/grpc++/impl/call.h",
+    "include/grpc++/impl/channel_argument_option.h",
+    "include/grpc++/impl/client_unary_call.h",
+    "include/grpc++/impl/codegen/core_codegen.h",
+    "include/grpc++/impl/grpc_library.h",
+    "include/grpc++/impl/method_handler_impl.h",
+    "include/grpc++/impl/rpc_method.h",
+    "include/grpc++/impl/rpc_service_method.h",
+    "include/grpc++/impl/serialization_traits.h",
+    "include/grpc++/impl/server_builder_option.h",
+    "include/grpc++/impl/server_builder_plugin.h",
+    "include/grpc++/impl/server_initializer.h",
+    "include/grpc++/impl/service_type.h",
+    "include/grpc++/impl/sync_cxx11.h",
+    "include/grpc++/impl/sync_no_cxx11.h",
+    "include/grpc++/resource_quota.h",
+    "include/grpc++/security/auth_context.h",
+    "include/grpc++/security/auth_metadata_processor.h",
+    "include/grpc++/security/credentials.h",
+    "include/grpc++/security/server_credentials.h",
+    "include/grpc++/server.h",
+    "include/grpc++/server_builder.h",
+    "include/grpc++/server_context.h",
+    "include/grpc++/server_posix.h",
+    "include/grpc++/support/async_stream.h",
+    "include/grpc++/support/async_unary_call.h",
+    "include/grpc++/support/byte_buffer.h",
+    "include/grpc++/support/channel_arguments.h",
+    "include/grpc++/support/config.h",
+    "include/grpc++/support/slice.h",
+    "include/grpc++/support/status.h",
+    "include/grpc++/support/status_code_enum.h",
+    "include/grpc++/support/string_ref.h",
+    "include/grpc++/support/stub_options.h",
+    "include/grpc++/support/sync_stream.h",
+    "include/grpc++/support/time.h",
+]
+
 grpc_cc_library(
     name = "grpc++",
     srcs = [
@@ -129,6 +226,7 @@
         "src/cpp/server/secure_server_credentials.h",
     ],
     language = "c++",
+    public_hdrs = GRPCXX_PUBLIC_HDRS,
     standalone = True,
     deps = [
         "gpr",
@@ -447,9 +545,9 @@
 
 grpc_cc_library(
     name = "grpc_trace",
-    language = "c",
     srcs = ["src/core/lib/debug/trace.c"],
     hdrs = ["src/core/lib/debug/trace.h"],
+    language = "c",
     deps = [":gpr"],
 )
 
@@ -1306,103 +1404,6 @@
     ],
 )
 
-# TODO(ctiller): layer grpc atop grpc_unsecure, layer grpc++ atop grpc++_unsecure
-GRPCXX_SRCS = [
-    "src/cpp/client/channel_cc.cc",
-    "src/cpp/client/client_context.cc",
-    "src/cpp/client/create_channel.cc",
-    "src/cpp/client/create_channel_internal.cc",
-    "src/cpp/client/create_channel_posix.cc",
-    "src/cpp/client/credentials_cc.cc",
-    "src/cpp/client/generic_stub.cc",
-    "src/cpp/common/channel_arguments.cc",
-    "src/cpp/common/channel_filter.cc",
-    "src/cpp/common/completion_queue_cc.cc",
-    "src/cpp/common/core_codegen.cc",
-    "src/cpp/common/resource_quota_cc.cc",
-    "src/cpp/common/rpc_method.cc",
-    "src/cpp/common/version_cc.cc",
-    "src/cpp/server/async_generic_service.cc",
-    "src/cpp/server/channel_argument_option.cc",
-    "src/cpp/server/create_default_thread_pool.cc",
-    "src/cpp/server/dynamic_thread_pool.cc",
-    "src/cpp/server/health/default_health_check_service.cc",
-    "src/cpp/server/health/health.pb.c",
-    "src/cpp/server/health/health_check_service.cc",
-    "src/cpp/server/health/health_check_service_server_builder_option.cc",
-    "src/cpp/server/server_builder.cc",
-    "src/cpp/server/server_cc.cc",
-    "src/cpp/server/server_context.cc",
-    "src/cpp/server/server_credentials.cc",
-    "src/cpp/server/server_posix.cc",
-    "src/cpp/thread_manager/thread_manager.cc",
-    "src/cpp/util/byte_buffer_cc.cc",
-    "src/cpp/util/slice_cc.cc",
-    "src/cpp/util/status.cc",
-    "src/cpp/util/string_ref.cc",
-    "src/cpp/util/time_cc.cc",
-]
-
-GRPCXX_HDRS = [
-    "src/cpp/client/create_channel_internal.h",
-    "src/cpp/common/channel_filter.h",
-    "src/cpp/server/dynamic_thread_pool.h",
-    "src/cpp/server/health/default_health_check_service.h",
-    "src/cpp/server/health/health.pb.h",
-    "src/cpp/server/thread_pool_interface.h",
-    "src/cpp/thread_manager/thread_manager.h",
-]
-
-GRPCXX_PUBLIC_HDRS = [
-    "include/grpc++/alarm.h",
-    "include/grpc++/channel.h",
-    "include/grpc++/client_context.h",
-    "include/grpc++/completion_queue.h",
-    "include/grpc++/create_channel.h",
-    "include/grpc++/create_channel_posix.h",
-    "include/grpc++/ext/health_check_service_server_builder_option.h",
-    "include/grpc++/generic/async_generic_service.h",
-    "include/grpc++/generic/generic_stub.h",
-    "include/grpc++/grpc++.h",
-    "include/grpc++/health_check_service_interface.h",
-    "include/grpc++/impl/call.h",
-    "include/grpc++/impl/channel_argument_option.h",
-    "include/grpc++/impl/client_unary_call.h",
-    "include/grpc++/impl/codegen/core_codegen.h",
-    "include/grpc++/impl/grpc_library.h",
-    "include/grpc++/impl/method_handler_impl.h",
-    "include/grpc++/impl/rpc_method.h",
-    "include/grpc++/impl/rpc_service_method.h",
-    "include/grpc++/impl/serialization_traits.h",
-    "include/grpc++/impl/server_builder_option.h",
-    "include/grpc++/impl/server_builder_plugin.h",
-    "include/grpc++/impl/server_initializer.h",
-    "include/grpc++/impl/service_type.h",
-    "include/grpc++/impl/sync_cxx11.h",
-    "include/grpc++/impl/sync_no_cxx11.h",
-    "include/grpc++/resource_quota.h",
-    "include/grpc++/security/auth_context.h",
-    "include/grpc++/security/auth_metadata_processor.h",
-    "include/grpc++/security/credentials.h",
-    "include/grpc++/security/server_credentials.h",
-    "include/grpc++/server.h",
-    "include/grpc++/server_builder.h",
-    "include/grpc++/server_context.h",
-    "include/grpc++/server_posix.h",
-    "include/grpc++/support/async_stream.h",
-    "include/grpc++/support/async_unary_call.h",
-    "include/grpc++/support/byte_buffer.h",
-    "include/grpc++/support/channel_arguments.h",
-    "include/grpc++/support/config.h",
-    "include/grpc++/support/slice.h",
-    "include/grpc++/support/status.h",
-    "include/grpc++/support/status_code_enum.h",
-    "include/grpc++/support/string_ref.h",
-    "include/grpc++/support/stub_options.h",
-    "include/grpc++/support/sync_stream.h",
-    "include/grpc++/support/time.h",
-]
-
 grpc_cc_library(
     name = "grpc++_base",
     srcs = GRPCXX_SRCS,