diff --git a/components/background_hang_monitor/tests/hang_monitor_tests.rs b/components/background_hang_monitor/tests/hang_monitor_tests.rs
index d7e6dcf268d..2ecb526e152 100644
--- a/components/background_hang_monitor/tests/hang_monitor_tests.rs
+++ b/components/background_hang_monitor/tests/hang_monitor_tests.rs
@@ -6,18 +6,63 @@ use background_hang_monitor::HangMonitorRegister;
 use ipc_channel::ipc;
 use msg::constellation_msg::ScriptHangAnnotation;
 use msg::constellation_msg::TEST_PIPELINE_ID;
-use msg::constellation_msg::{HangAlert, HangAnnotation};
+use msg::constellation_msg::{HangAlert, HangAnnotation, HangMonitorAlert};
 use msg::constellation_msg::{MonitoredComponentId, MonitoredComponentType};
 use std::thread;
 use std::time::Duration;
 
+#[test]
+#[cfg(target_os = "macos")]
+fn test_sampler() {
+    use msg::constellation_msg::SamplerControlMsg;
+    use serde_json::Value;
+
+    let (background_hang_monitor_ipc_sender, background_hang_monitor_receiver) =
+        ipc::channel().expect("ipc channel failure");
+    let (sampler_sender, sampler_receiver) = ipc::channel().expect("ipc channel failure");
+
+    let background_hang_monitor_register =
+        HangMonitorRegister::init(background_hang_monitor_ipc_sender.clone(), sampler_receiver);
+    let _background_hang_monitor = background_hang_monitor_register.register_component(
+        MonitoredComponentId(TEST_PIPELINE_ID, MonitoredComponentType::Script),
+        Duration::from_millis(10),
+        Duration::from_millis(1000),
+    );
+
+    const RATE: u64 = 10;
+    sampler_sender
+        .send(SamplerControlMsg::Enable(Duration::from_millis(RATE)))
+        .unwrap();
+
+    thread::sleep(Duration::from_millis(30));
+
+    sampler_sender.send(SamplerControlMsg::Disable).unwrap();
+
+    loop {
+        match background_hang_monitor_receiver.recv().unwrap() {
+            HangMonitorAlert::Hang(_) => continue,
+            HangMonitorAlert::Profile(ref bytes) => {
+                let json: Value = serde_json::from_slice(bytes).unwrap();
+                let rate = json["rate"].as_u64().unwrap();
+                assert_eq!(rate, RATE);
+                let data = json["data"].as_array().unwrap();
+                assert!(data.len() > 1);
+                assert_eq!(data[0]["name"].as_str().unwrap(), "test_sampler");
+                assert!(data[0]["frames"].as_array().unwrap().len() > 0);
+                break;
+            },
+        }
+    }
+}
+
 #[test]
 fn test_hang_monitoring() {
     let (background_hang_monitor_ipc_sender, background_hang_monitor_receiver) =
         ipc::channel().expect("ipc channel failure");
+    let (_sampler_sender, sampler_receiver) = ipc::channel().expect("ipc channel failure");
 
     let background_hang_monitor_register =
-        HangMonitorRegister::init(background_hang_monitor_ipc_sender.clone());
+        HangMonitorRegister::init(background_hang_monitor_ipc_sender.clone(), sampler_receiver);
     let background_hang_monitor = background_hang_monitor_register.register_component(
         MonitoredComponentId(TEST_PIPELINE_ID, MonitoredComponentType::Script),
         Duration::from_millis(10),
@@ -33,11 +78,11 @@ fn test_hang_monitoring() {
 
     // Check for a transient hang alert.
     match background_hang_monitor_receiver.recv().unwrap() {
-        HangAlert::Transient(component_id, _annotation) => {
+        HangMonitorAlert::Hang(HangAlert::Transient(component_id, _annotation)) => {
             let expected = MonitoredComponentId(TEST_PIPELINE_ID, MonitoredComponentType::Script);
             assert_eq!(expected, component_id);
         },
-        HangAlert::Permanent(..) => unreachable!(),
+        _ => unreachable!(),
     }
 
     // Sleep until the "permanent" timeout has been reached.
@@ -45,11 +90,11 @@ fn test_hang_monitoring() {
 
     // Check for a permanent hang alert.
     match background_hang_monitor_receiver.recv().unwrap() {
-        HangAlert::Permanent(component_id, _annotation, _profile) => {
+        HangMonitorAlert::Hang(HangAlert::Permanent(component_id, _annotation, _profile)) => {
             let expected = MonitoredComponentId(TEST_PIPELINE_ID, MonitoredComponentType::Script);
             assert_eq!(expected, component_id);
         },
-        HangAlert::Transient(..) => unreachable!(),
+        _ => unreachable!(),
     }
 
     // Now the component is not hanging anymore.
@@ -61,11 +106,11 @@ fn test_hang_monitoring() {
 
     // Check for a transient hang alert.
     match background_hang_monitor_receiver.recv().unwrap() {
-        HangAlert::Transient(component_id, _annotation) => {
+        HangMonitorAlert::Hang(HangAlert::Transient(component_id, _annotation)) => {
             let expected = MonitoredComponentId(TEST_PIPELINE_ID, MonitoredComponentType::Script);
             assert_eq!(expected, component_id);
         },
-        HangAlert::Permanent(..) => unreachable!(),
+        _ => unreachable!(),
     }
 
     // Now the component is waiting for a new task.
@@ -85,11 +130,11 @@ fn test_hang_monitoring() {
 
     // We're getting new hang alerts for the latest task.
     match background_hang_monitor_receiver.recv().unwrap() {
-        HangAlert::Transient(component_id, _annotation) => {
+        HangMonitorAlert::Hang(HangAlert::Transient(component_id, _annotation)) => {
             let expected = MonitoredComponentId(TEST_PIPELINE_ID, MonitoredComponentType::Script);
             assert_eq!(expected, component_id);
         },
-        HangAlert::Permanent(..) => unreachable!(),
+        _ => unreachable!(),
     }
 
     // No new alert yet
@@ -110,9 +155,10 @@ fn test_hang_monitoring() {
 fn test_hang_monitoring_unregister() {
     let (background_hang_monitor_ipc_sender, background_hang_monitor_receiver) =
         ipc::channel().expect("ipc channel failure");
+    let (_sampler_sender, sampler_receiver) = ipc::channel().expect("ipc channel failure");
 
     let background_hang_monitor_register =
-        HangMonitorRegister::init(background_hang_monitor_ipc_sender.clone());
+        HangMonitorRegister::init(background_hang_monitor_ipc_sender.clone(), sampler_receiver);
     let background_hang_monitor = background_hang_monitor_register.register_component(
         MonitoredComponentId(TEST_PIPELINE_ID, MonitoredComponentType::Script),
         Duration::from_millis(10),