Fix some new warnings

components/background_hang_monitor/background_hang_monitor.rs

@@ -26,7 +26,7 @@ impl HangMonitorRegister {
     pub fn init(
         constellation_chan: IpcSender<HangMonitorAlert>,
         control_port: IpcReceiver<SamplerControlMsg>,
-    ) -> Box<BackgroundHangMonitorRegister> {
+    ) -> Box<dyn BackgroundHangMonitorRegister> {
         let (sender, port) = unbounded();
         let _ = thread::Builder::new().spawn(move || {
             let mut monitor =
@@ -48,7 +48,7 @@ impl BackgroundHangMonitorRegister for HangMonitorRegister {
         component_id: MonitoredComponentId,
         transient_hang_timeout: Duration,
         permanent_hang_timeout: Duration,
-    ) -> Box<BackgroundHangMonitor> {
+    ) -> Box<dyn BackgroundHangMonitor> {
         let bhm_chan = BackgroundHangMonitorChan::new(self.sender.clone(), component_id);
 
         #[cfg(all(
@@ -77,7 +77,7 @@ impl BackgroundHangMonitorRegister for HangMonitorRegister {
 }
 
 impl BackgroundHangMonitorClone for HangMonitorRegister {
-    fn clone_box(&self) -> Box<BackgroundHangMonitorRegister> {
+    fn clone_box(&self) -> Box<dyn BackgroundHangMonitorRegister> {
         Box::new(self.clone())
     }
 }
@@ -85,7 +85,7 @@ impl BackgroundHangMonitorClone for HangMonitorRegister {
 /// Messages sent from monitored components to the monitor.
 pub enum MonitoredComponentMsg {
     /// Register component for monitoring,
-    Register(Box<Sampler>, Option<String>, Duration, Duration),
+    Register(Box<dyn Sampler>, Option<String>, Duration, Duration),
     /// Unregister component for monitoring.
     Unregister,
     /// Notify start of new activity for a given component,
@@ -142,7 +142,7 @@ impl BackgroundHangMonitor for BackgroundHangMonitorChan {
 }
 
 struct MonitoredComponent {
-    sampler: Box<Sampler>,
+    sampler: Box<dyn Sampler>,
     last_activity: Instant,
     last_annotation: Option<HangAnnotation>,
     transient_hang_timeout: Duration,

components/background_hang_monitor/sampler.rs

@@ -17,7 +17,7 @@ pub struct DummySampler;
 
 impl DummySampler {
     #[allow(dead_code)]
-    pub fn new() -> Box<Sampler> {
+    pub fn new() -> Box<dyn Sampler> {
         Box::new(DummySampler)
     }
 }

components/background_hang_monitor/sampler_linux.rs

@@ -128,7 +128,7 @@ pub struct LinuxSampler {
 
 impl LinuxSampler {
     #[allow(unsafe_code, dead_code)]
-    pub fn new() -> Box<Sampler> {
+    pub fn new() -> Box<dyn Sampler> {
         let thread_id = unsafe { libc::syscall(libc::SYS_gettid) as libc::pid_t };
         let handler = SigHandler::SigAction(sigprof_handler);
         let action = SigAction::new(

components/background_hang_monitor/sampler_mac.rs

@@ -16,7 +16,7 @@ pub struct MacOsSampler {
 
 impl MacOsSampler {
     #[allow(unsafe_code)]
-    pub fn new() -> Box<Sampler> {
+    pub fn new() -> Box<dyn Sampler> {
         let thread_id = unsafe { mach::mach_init::mach_thread_self() };
         Box::new(MacOsSampler { thread_id })
     }

components/background_hang_monitor/sampler_windows.rs

@@ -13,7 +13,7 @@ pub struct WindowsSampler {
 
 impl WindowsSampler {
     #[allow(unsafe_code, dead_code)]
-    pub fn new() -> Box<Sampler> {
+    pub fn new() -> Box<dyn Sampler> {
         let thread_id = 0; // TODO: use winapi::um::processthreadsapi::GetThreadId
         Box::new(WindowsSampler { thread_id })
     }