Add C++ targets, especially for gRPC services. (#212)

Author: g-easy

src/opencensus/proto/agent/common/v1/BUILD.bazel

@@ -32,3 +32,8 @@ go_proto_library(
         "@com_github_golang_protobuf//ptypes/timestamp:go_default_library",
     ],
 )
+
+cc_proto_library(
+    name = "common_proto_cc",
+    deps = [":common_proto"],
+)

src/opencensus/proto/agent/metrics/v1/BUILD.bazel

@@ -16,6 +16,7 @@ package(default_visibility = ["//visibility:public"])
 
 load("@grpc_java//:java_grpc_library.bzl", "java_grpc_library")
 load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
+load("@com_github_grpc_grpc//bazel:cc_grpc_library.bzl", "cc_grpc_library")
 
 proto_library(
     name = "metrics_service_proto",
@@ -32,6 +33,13 @@ cc_proto_library(
     deps = [":metrics_service_proto"],
 )
 
+cc_grpc_library(
+    name = "metrics_service_grpc_cc",
+    srcs = [":metrics_service_proto"],
+    deps = [":metrics_service_proto_cc"],
+    grpc_only = True,
+)
+
 java_proto_library(
     name = "metrics_service_proto_java",
     deps = [":metrics_service_proto"],

src/opencensus/proto/agent/trace/v1/BUILD.bazel

@@ -16,6 +16,7 @@ package(default_visibility = ["//visibility:public"])
 
 load("@grpc_java//:java_grpc_library.bzl", "java_grpc_library")
 load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
+load("@com_github_grpc_grpc//bazel:cc_grpc_library.bzl", "cc_grpc_library")
 
 proto_library(
     name = "trace_service_proto",
@@ -33,6 +34,13 @@ cc_proto_library(
     deps = [":trace_service_proto"],
 )
 
+cc_grpc_library(
+    name = "trace_service_grpc_cc",
+    srcs = [":trace_service_proto"],
+    deps = [":trace_service_proto_cc"],
+    grpc_only = True,
+)
+
 java_proto_library(
     name = "trace_service_proto_java",
     deps = [":trace_service_proto"],