Merge pull request #13709 from ZhouyihaiDing/readme

PHP: update readme file
diff --git a/src/compiler/csharp_generator.cc b/src/compiler/csharp_generator.cc
index 14173e0..1c51f6d 100644
--- a/src/compiler/csharp_generator.cc
+++ b/src/compiler/csharp_generator.cc
@@ -680,14 +680,19 @@
     out.Print("using grpc = global::Grpc.Core;\n");
     out.Print("\n");
 
-    out.Print("namespace $namespace$ {\n", "namespace", GetFileNamespace(file));
-    out.Indent();
+    grpc::string file_namespace = GetFileNamespace(file);
+    if (file_namespace != "") {
+      out.Print("namespace $namespace$ {\n", "namespace", file_namespace);
+      out.Indent();
+    }
     for (int i = 0; i < file->service_count(); i++) {
       GenerateService(&out, file->service(i), generate_client, generate_server,
                       internal_access);
     }
-    out.Outdent();
-    out.Print("}\n");
+    if (file_namespace != "") {
+      out.Outdent();
+      out.Print("}\n");
+    }
     out.Print("#endregion\n");
   }
   return output;
diff --git a/test/core/end2end/tests/retry_server_pushback_delay.cc b/test/core/end2end/tests/retry_server_pushback_delay.cc
index f6a9796..221b416 100644
--- a/test/core/end2end/tests/retry_server_pushback_delay.cc
+++ b/test/core/end2end/tests/retry_server_pushback_delay.cc
@@ -249,7 +249,7 @@
           retry_delay.tv_sec, retry_delay.tv_nsec);
   GPR_ASSERT(retry_delay.tv_sec >= 1);
   if (retry_delay.tv_sec == 1) {
-    GPR_ASSERT(retry_delay.tv_nsec >= 900000000);
+    GPR_ASSERT(retry_delay.tv_nsec >= 800000000);
   }
 
   peer = grpc_call_get_peer(s);
diff --git a/test/core/gpr/arena_test.cc b/test/core/gpr/arena_test.cc
index 111414e..3e7c906 100644
--- a/test/core/gpr/arena_test.cc
+++ b/test/core/gpr/arena_test.cc
@@ -71,7 +71,7 @@
   static const size_t allocs_##name[] = {__VA_ARGS__}; \
   test(#name, init_size, allocs_##name, GPR_ARRAY_SIZE(allocs_##name))
 
-#define CONCURRENT_TEST_THREADS 100
+#define CONCURRENT_TEST_THREADS 10
 
 size_t concurrent_test_iterations() {
   if (sizeof(void*) < 8) return 1000;
diff --git a/tools/run_tests/python_utils/upload_rbe_results.py b/tools/run_tests/python_utils/upload_rbe_results.py
index 5955b37..a2dd0bc 100644
--- a/tools/run_tests/python_utils/upload_rbe_results.py
+++ b/tools/run_tests/python_utils/upload_rbe_results.py
@@ -175,8 +175,8 @@
                     'build_id':
                     os.getenv('KOKORO_BUILD_NUMBER'),
                     'build_url':
-                    'https://sponge.corp.google.com/invocation?id=%s' %
-                    os.getenv('KOKORO_BUILD_ID'),
+                    'https://source.cloud.google.com/results/invocations/%s' %
+                    invocation_id,
                     'test_target':
                     action['id']['targetId'],
                     'test_case':