Populate latency field in final_info.
diff --git a/test/core/channel/channel_stack_test.c b/test/core/channel/channel_stack_test.c
index 26fc3dc..f1816ae 100644
--- a/test/core/channel/channel_stack_test.c
+++ b/test/core/channel/channel_stack_test.c
@@ -138,7 +138,8 @@
   call_stack = gpr_malloc(channel_stack->call_stack_size);
   grpc_error *error = grpc_call_stack_init(
       &exec_ctx, channel_stack, 1, free_call, call_stack, NULL, NULL, path,
-      gpr_inf_future(GPR_CLOCK_MONOTONIC), call_stack);
+      gpr_now(GPR_CLOCK_MONOTONIC), gpr_inf_future(GPR_CLOCK_MONOTONIC),
+      call_stack);
   GPR_ASSERT(error == GRPC_ERROR_NONE);
   GPR_ASSERT(call_stack->count == 1);
   call_elem = grpc_call_stack_element(call_stack, 0);
diff --git a/test/core/end2end/end2end_nosec_tests.c b/test/core/end2end/end2end_nosec_tests.c
index caaa97c..6bbc58c 100644
--- a/test/core/end2end/end2end_nosec_tests.c
+++ b/test/core/end2end/end2end_nosec_tests.c
@@ -73,6 +73,8 @@
 extern void filter_call_init_fails_pre_init(void);
 extern void filter_causes_close(grpc_end2end_test_config config);
 extern void filter_causes_close_pre_init(void);
+extern void filter_latency(grpc_end2end_test_config config);
+extern void filter_latency_pre_init(void);
 extern void graceful_server_shutdown(grpc_end2end_test_config config);
 extern void graceful_server_shutdown_pre_init(void);
 extern void high_initial_seqno(grpc_end2end_test_config config);
@@ -150,6 +152,7 @@
   empty_batch_pre_init();
   filter_call_init_fails_pre_init();
   filter_causes_close_pre_init();
+  filter_latency_pre_init();
   graceful_server_shutdown_pre_init();
   high_initial_seqno_pre_init();
   hpack_size_pre_init();
@@ -203,6 +206,7 @@
     empty_batch(config);
     filter_call_init_fails(config);
     filter_causes_close(config);
+    filter_latency(config);
     graceful_server_shutdown(config);
     high_initial_seqno(config);
     hpack_size(config);
@@ -296,6 +300,10 @@
       filter_causes_close(config);
       continue;
     }
+    if (0 == strcmp("filter_latency", argv[i])) {
+      filter_latency(config);
+      continue;
+    }
     if (0 == strcmp("graceful_server_shutdown", argv[i])) {
       graceful_server_shutdown(config);
       continue;
diff --git a/test/core/end2end/end2end_tests.c b/test/core/end2end/end2end_tests.c
index 6d17e68..9d49e14 100644
--- a/test/core/end2end/end2end_tests.c
+++ b/test/core/end2end/end2end_tests.c
@@ -75,6 +75,8 @@
 extern void filter_call_init_fails_pre_init(void);
 extern void filter_causes_close(grpc_end2end_test_config config);
 extern void filter_causes_close_pre_init(void);
+extern void filter_latency(grpc_end2end_test_config config);
+extern void filter_latency_pre_init(void);
 extern void graceful_server_shutdown(grpc_end2end_test_config config);
 extern void graceful_server_shutdown_pre_init(void);
 extern void high_initial_seqno(grpc_end2end_test_config config);
@@ -153,6 +155,7 @@
   empty_batch_pre_init();
   filter_call_init_fails_pre_init();
   filter_causes_close_pre_init();
+  filter_latency_pre_init();
   graceful_server_shutdown_pre_init();
   high_initial_seqno_pre_init();
   hpack_size_pre_init();
@@ -207,6 +210,7 @@
     empty_batch(config);
     filter_call_init_fails(config);
     filter_causes_close(config);
+    filter_latency(config);
     graceful_server_shutdown(config);
     high_initial_seqno(config);
     hpack_size(config);
@@ -304,6 +308,10 @@
       filter_causes_close(config);
       continue;
     }
+    if (0 == strcmp("filter_latency", argv[i])) {
+      filter_latency(config);
+      continue;
+    }
     if (0 == strcmp("graceful_server_shutdown", argv[i])) {
       graceful_server_shutdown(config);
       continue;
diff --git a/test/core/end2end/gen_build_yaml.py b/test/core/end2end/gen_build_yaml.py
index 7f33e07..a286bbc 100755
--- a/test/core/end2end/gen_build_yaml.py
+++ b/test/core/end2end/gen_build_yaml.py
@@ -111,6 +111,7 @@
     'empty_batch': default_test_options,
     'filter_causes_close': default_test_options,
     'filter_call_init_fails': default_test_options,
+    'filter_latency': default_test_options,
     'graceful_server_shutdown': default_test_options._replace(cpu_cost=LOWCPU),
     'hpack_size': default_test_options._replace(proxyable=False,
                                                 traceable=False),
diff --git a/test/core/end2end/tests/filter_latency.c b/test/core/end2end/tests/filter_latency.c
new file mode 100644
index 0000000..b64635e
--- /dev/null
+++ b/test/core/end2end/tests/filter_latency.c
@@ -0,0 +1,338 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "test/core/end2end/end2end_tests.h"
+
+#include <limits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <grpc/byte_buffer.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/time.h>
+#include <grpc/support/useful.h>
+
+#include "src/core/lib/channel/channel_stack_builder.h"
+#include "src/core/lib/surface/channel_init.h"
+#include "test/core/end2end/cq_verifier.h"
+
+enum { TIMEOUT = 200000 };
+
+static bool g_enable_filter = false;
+static gpr_timespec g_client_latency;
+static gpr_timespec g_server_latency;
+
+static void *tag(intptr_t t) { return (void *)t; }
+
+static grpc_end2end_test_fixture begin_test(grpc_end2end_test_config config,
+                                            const char *test_name,
+                                            grpc_channel_args *client_args,
+                                            grpc_channel_args *server_args) {
+  grpc_end2end_test_fixture f;
+  gpr_log(GPR_INFO, "%s/%s", test_name, config.name);
+  f = config.create_fixture(client_args, server_args);
+  config.init_server(&f, server_args);
+  config.init_client(&f, client_args);
+  return f;
+}
+
+static gpr_timespec n_seconds_time(int n) {
+  return GRPC_TIMEOUT_SECONDS_TO_DEADLINE(n);
+}
+
+static gpr_timespec five_seconds_time(void) { return n_seconds_time(5); }
+
+static void drain_cq(grpc_completion_queue *cq) {
+  grpc_event ev;
+  do {
+    ev = grpc_completion_queue_next(cq, five_seconds_time(), NULL);
+  } while (ev.type != GRPC_QUEUE_SHUTDOWN);
+}
+
+static void shutdown_server(grpc_end2end_test_fixture *f) {
+  if (!f->server) return;
+  grpc_server_shutdown_and_notify(f->server, f->cq, tag(1000));
+  GPR_ASSERT(grpc_completion_queue_pluck(
+                 f->cq, tag(1000), GRPC_TIMEOUT_SECONDS_TO_DEADLINE(5), NULL)
+                 .type == GRPC_OP_COMPLETE);
+  grpc_server_destroy(f->server);
+  f->server = NULL;
+}
+
+static void shutdown_client(grpc_end2end_test_fixture *f) {
+  if (!f->client) return;
+  grpc_channel_destroy(f->client);
+  f->client = NULL;
+}
+
+static void end_test(grpc_end2end_test_fixture *f) {
+  shutdown_server(f);
+  shutdown_client(f);
+
+  grpc_completion_queue_shutdown(f->cq);
+  drain_cq(f->cq);
+  grpc_completion_queue_destroy(f->cq);
+}
+
+// Simple request via a server filter that always fails to initialize
+// the call.
+static void test_request(grpc_end2end_test_config config) {
+  grpc_call *c;
+  grpc_call *s;
+  gpr_slice request_payload_slice = gpr_slice_from_copied_string("hello world");
+  grpc_byte_buffer *request_payload =
+      grpc_raw_byte_buffer_create(&request_payload_slice, 1);
+  gpr_timespec deadline = five_seconds_time();
+  grpc_end2end_test_fixture f =
+      begin_test(config, "filter_latency", NULL, NULL);
+  cq_verifier *cqv = cq_verifier_create(f.cq);
+  grpc_op ops[6];
+  grpc_op *op;
+  grpc_metadata_array initial_metadata_recv;
+  grpc_metadata_array trailing_metadata_recv;
+  grpc_metadata_array request_metadata_recv;
+  grpc_byte_buffer *request_payload_recv = NULL;
+  grpc_call_details call_details;
+  grpc_status_code status;
+  grpc_call_error error;
+  char *details = NULL;
+  size_t details_capacity = 0;
+  int was_cancelled = 2;
+
+  g_client_latency = gpr_time_0(GPR_TIMESPAN);
+  g_server_latency = gpr_time_0(GPR_TIMESPAN);
+  const gpr_timespec start_time = gpr_now(GPR_CLOCK_MONOTONIC); 
+
+  c = grpc_channel_create_call(f.client, NULL, GRPC_PROPAGATE_DEFAULTS, f.cq,
+                               "/foo", "foo.test.google.fr", deadline, NULL);
+  GPR_ASSERT(c);
+
+  grpc_metadata_array_init(&initial_metadata_recv);
+  grpc_metadata_array_init(&trailing_metadata_recv);
+  grpc_metadata_array_init(&request_metadata_recv);
+  grpc_call_details_init(&call_details);
+
+  memset(ops, 0, sizeof(ops));
+  op = ops;
+  op->op = GRPC_OP_SEND_INITIAL_METADATA;
+  op->data.send_initial_metadata.count = 0;
+  op->data.send_initial_metadata.metadata = NULL;
+  op->flags = 0;
+  op->reserved = NULL;
+  op++;
+  op->op = GRPC_OP_SEND_MESSAGE;
+  op->data.send_message = request_payload;
+  op->flags = 0;
+  op->reserved = NULL;
+  op++;
+  op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
+  op->flags = 0;
+  op->reserved = NULL;
+  op++;
+  op->op = GRPC_OP_RECV_INITIAL_METADATA;
+  op->data.recv_initial_metadata = &initial_metadata_recv;
+  op->flags = 0;
+  op->reserved = NULL;
+  op++;
+  op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
+  op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
+  op->data.recv_status_on_client.status = &status;
+  op->data.recv_status_on_client.status_details = &details;
+  op->data.recv_status_on_client.status_details_capacity = &details_capacity;
+  op->flags = 0;
+  op->reserved = NULL;
+  op++;
+  error = grpc_call_start_batch(c, ops, (size_t)(op - ops), tag(1), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
+
+  error =
+      grpc_server_request_call(f.server, &s, &call_details,
+                               &request_metadata_recv, f.cq, f.cq, tag(101));
+  GPR_ASSERT(GRPC_CALL_OK == error);
+
+  CQ_EXPECT_COMPLETION(cqv, tag(101), 1);
+  cq_verify(cqv);
+
+  memset(ops, 0, sizeof(ops));
+  op = ops;
+  op->op = GRPC_OP_SEND_INITIAL_METADATA;
+  op->data.send_initial_metadata.count = 0;
+  op->flags = 0;
+  op->reserved = NULL;
+  op++;
+  op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
+  op->data.send_status_from_server.trailing_metadata_count = 0;
+  op->data.send_status_from_server.status = GRPC_STATUS_UNIMPLEMENTED;
+  op->data.send_status_from_server.status_details = "xyz";
+  op->flags = 0;
+  op->reserved = NULL;
+  op++;
+  op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
+  op->data.recv_close_on_server.cancelled = &was_cancelled;
+  op->flags = 0;
+  op->reserved = NULL;
+  op++;
+  error = grpc_call_start_batch(s, ops, (size_t)(op - ops), tag(102), NULL);
+  GPR_ASSERT(GRPC_CALL_OK == error);
+
+  CQ_EXPECT_COMPLETION(cqv, tag(102), 1);
+  CQ_EXPECT_COMPLETION(cqv, tag(1), 1);
+  cq_verify(cqv);
+
+  GPR_ASSERT(status == GRPC_STATUS_UNIMPLEMENTED);
+  GPR_ASSERT(0 == strcmp(details, "xyz"));
+
+  gpr_free(details);
+  grpc_metadata_array_destroy(&initial_metadata_recv);
+  grpc_metadata_array_destroy(&trailing_metadata_recv);
+  grpc_metadata_array_destroy(&request_metadata_recv);
+  grpc_call_details_destroy(&call_details);
+
+  grpc_call_destroy(c);
+  grpc_call_destroy(s);
+
+  const gpr_timespec end_time = gpr_now(GPR_CLOCK_MONOTONIC);
+  const gpr_timespec max_latency = gpr_time_sub(end_time, start_time);
+
+  GPR_ASSERT(gpr_time_cmp(max_latency, g_client_latency) >= 0);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_0(GPR_TIMESPAN), g_client_latency) < 0);
+  GPR_ASSERT(gpr_time_cmp(max_latency, g_server_latency) >= 0);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_0(GPR_TIMESPAN), g_server_latency) < 0);
+
+  cq_verifier_destroy(cqv);
+
+  grpc_byte_buffer_destroy(request_payload);
+  grpc_byte_buffer_destroy(request_payload_recv);
+
+  end_test(&f);
+  config.tear_down_data(&f);
+}
+
+/*******************************************************************************
+ * Test filter
+ */
+
+static grpc_error *init_call_elem(grpc_exec_ctx *exec_ctx,
+                                  grpc_call_element *elem,
+                                  grpc_call_element_args *args) {
+  return GRPC_ERROR_NONE;
+}
+
+static void client_destroy_call_elem(
+    grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+    const grpc_call_final_info *final_info, void *and_free_memory) {
+  g_client_latency = final_info->stats.latency;
+}
+
+static void server_destroy_call_elem(
+    grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+    const grpc_call_final_info *final_info, void *and_free_memory) {
+  g_server_latency = final_info->stats.latency;
+}
+
+static void init_channel_elem(grpc_exec_ctx *exec_ctx,
+                              grpc_channel_element *elem,
+                              grpc_channel_element_args *args) {}
+
+static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
+                                 grpc_channel_element *elem) {}
+
+static const grpc_channel_filter test_client_filter = {
+    grpc_call_next_op,
+    grpc_channel_next_op,
+    0,
+    init_call_elem,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
+    client_destroy_call_elem,
+    0,
+    init_channel_elem,
+    destroy_channel_elem,
+    grpc_call_next_get_peer,
+    "filter_latency"};
+
+static const grpc_channel_filter test_server_filter = {
+    grpc_call_next_op,
+    grpc_channel_next_op,
+    0,
+    init_call_elem,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
+    server_destroy_call_elem,
+    0,
+    init_channel_elem,
+    destroy_channel_elem,
+    grpc_call_next_get_peer,
+    "filter_latency"};
+
+/*******************************************************************************
+ * Registration
+ */
+
+static bool maybe_add_filter(grpc_channel_stack_builder *builder, void *arg) {
+  grpc_channel_filter* filter = arg;
+  if (g_enable_filter) {
+    // Want to add the filter as close to the end as possible, to make
+    // sure that all of the filters work well together.  However, we
+    // can't add it at the very end, because the connected channel filter
+    // must be the last one.  So we add it right before the last one.
+    grpc_channel_stack_builder_iterator *it =
+        grpc_channel_stack_builder_create_iterator_at_last(builder);
+    GPR_ASSERT(grpc_channel_stack_builder_move_prev(it));
+    const bool retval = grpc_channel_stack_builder_add_filter_before(
+        it, filter, NULL, NULL);
+    grpc_channel_stack_builder_iterator_destroy(it);
+    return retval;
+  } else {
+    return true;
+  }
+}
+
+static void init_plugin(void) {
+  grpc_channel_init_register_stage(GRPC_CLIENT_CHANNEL, INT_MAX,
+                                   maybe_add_filter, (void*)&test_client_filter);
+  grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL, INT_MAX,
+                                   maybe_add_filter, (void*)&test_server_filter);
+}
+
+static void destroy_plugin(void) {}
+
+void filter_latency(grpc_end2end_test_config config) {
+  g_enable_filter = true;
+  test_request(config);
+  g_enable_filter = false;
+}
+
+void filter_latency_pre_init(void) {
+  grpc_register_plugin(init_plugin, destroy_plugin);
+}