Start reporting memory usage for Window and all nodes in all DOM trees for frame treese in script tasks.

components/script/document_loader.rs

@@ -12,7 +12,7 @@ use net_traits::AsyncResponseTarget;
 use std::sync::Arc;
 use url::Url;
 
-#[derive(JSTraceable, PartialEq, Clone, Debug)]
+#[derive(JSTraceable, PartialEq, Clone, Debug, HeapSizeOf)]
 pub enum LoadType {
     Image(Url),
     Script(Url),
@@ -33,17 +33,19 @@ impl LoadType {
     }
 }
 
-#[derive(JSTraceable)]
+#[derive(JSTraceable, HeapSizeOf)]
 pub struct DocumentLoader {
     /// We use an `Arc<ResourceTask>` here in order to avoid file descriptor exhaustion when there
     /// are lots of iframes.
+    #[ignore_heap_size_of = "channels are hard"]
     pub resource_task: Arc<ResourceTask>,
     notifier_data: Option<NotifierData>,
     blocking_loads: Vec<LoadType>,
 }
 
-#[derive(JSTraceable)]
+#[derive(JSTraceable, HeapSizeOf)]
 pub struct NotifierData {
+    #[ignore_heap_size_of = "trait objects are hard"]
     pub script_chan: Box<ScriptChan + Send>,
     pub pipeline: PipelineId,
 }

components/script/dom/bindings/cell.rs

@@ -16,7 +16,7 @@ use std::cell::{BorrowState, RefCell, Ref, RefMut};
 ///
 /// This extends the API of `core::cell::RefCell` to allow unsafe access in
 /// certain situations, with dynamic checking in debug builds.
-#[derive(Clone)]
+#[derive(Clone, HeapSizeOf)]
 pub struct DOMRefCell<T> {
     value: RefCell<T>,
 }

components/script/dom/bindings/codegen/CodegenRust.py

@@ -3314,7 +3314,7 @@ class CGEnum(CGThing):
 
         decl = """\
 #[repr(usize)]
-#[derive(JSTraceable, PartialEq, Copy, Clone)]
+#[derive(JSTraceable, PartialEq, Copy, Clone, HeapSizeOf)]
 pub enum %s {
     %s
 }

components/script/dom/bindings/js.rs

@@ -31,6 +31,7 @@ use js::jsapi::{JSObject, Heap, JSTracer};
 use js::jsval::JSVal;
 use layout_interface::TrustedNodeAddress;
 use script_task::STACK_ROOTS;
+use util::mem::HeapSizeOf;
 
 use core::nonzero::NonZero;
 use std::cell::{Cell, UnsafeCell};
@@ -44,6 +45,14 @@ pub struct JS<T> {
     ptr: NonZero<*const T>
 }
 
+// JS<T> is similar to Rc<T>, in that it's not always clear how to avoid double-counting.
+// For now, we choose not to follow any such pointers.
+impl<T> HeapSizeOf for JS<T> {
+    fn heap_size_of_children(&self) -> usize {
+        0
+    }
+}
+
 impl<T> JS<T> {
     /// Returns `LayoutJS<T>` containing the same pointer.
     pub unsafe fn to_layout(self) -> LayoutJS<T> {
@@ -226,7 +235,7 @@ impl<T: HeapGCValue+Copy> MutHeap<T> {
 /// place of traditional internal mutability to ensure that the proper GC
 /// barriers are enforced.
 #[must_root]
-#[derive(JSTraceable)]
+#[derive(JSTraceable, HeapSizeOf)]
 pub struct MutNullableHeap<T: HeapGCValue+Copy> {
     ptr: Cell<Option<T>>
 }

components/script/dom/bindings/utils.rs

@@ -16,6 +16,7 @@ use dom::bindings::js::Root;
 use dom::bindings::trace::trace_object;
 use dom::browsercontext;
 use dom::window;
+use util::mem::HeapSizeOf;
 use util::str::DOMString;
 
 use libc;
@@ -61,10 +62,18 @@ use js;
 use string_cache::{Atom, Namespace};
 
 /// Proxy handler for a WindowProxy.
+#[allow(raw_pointer_derive)]
 pub struct WindowProxyHandler(pub *const libc::c_void);
 
+impl HeapSizeOf for WindowProxyHandler {
+    fn heap_size_of_children(&self) -> usize {
+        //FIXME(#6907) this is a pointer to memory allocated by `new` in NewProxyHandler in rust-mozjs.
+        0
+    }
+}
+
 #[allow(raw_pointer_derive)]
-#[derive(JSTraceable)]
+#[derive(JSTraceable, HeapSizeOf)]
 /// Static data associated with a global object.
 pub struct GlobalStaticData {
     /// The WindowProxy proxy handler for this global.
@@ -416,8 +425,10 @@ pub fn reflect_dom_object<T: Reflectable>
 #[allow(raw_pointer_derive, unrooted_must_root)]
 #[must_root]
 #[servo_lang = "reflector"]
+#[derive(HeapSizeOf)]
 // If you're renaming or moving this field, update the path in plugins::reflector as well
 pub struct Reflector {
+    #[ignore_heap_size_of = "defined and measured in rust-mozjs"]
     object: UnsafeCell<*mut JSObject>,
 }
 

components/script/dom/browsercontext.rs

@@ -27,7 +27,7 @@ use js::{JSTrue, JSFalse};
 use std::ptr;
 use std::default::Default;
 
-#[derive(JSTraceable)]
+#[derive(JSTraceable, HeapSizeOf)]
 #[privatize]
 #[allow(raw_pointer_derive)]
 #[must_root]
@@ -88,7 +88,7 @@ impl BrowsingContext {
 // without a reflector, so we don't mark this as #[dom_struct]
 #[must_root]
 #[privatize]
-#[derive(JSTraceable)]
+#[derive(JSTraceable, HeapSizeOf)]
 pub struct SessionHistoryEntry {
     document: JS<Document>,
     children: Vec<BrowsingContext>

components/script/dom/characterdata.rs

@@ -24,6 +24,7 @@ use std::cell::Ref;
 
 // https://dom.spec.whatwg.org/#characterdata
 #[dom_struct]
+#[derive(HeapSizeOf)]
 pub struct CharacterData {
     node: Node,
     data: DOMRefCell<DOMString>,
@@ -150,7 +151,7 @@ impl<'a> CharacterDataMethods for &'a CharacterData {
 }
 
 /// The different types of CharacterData.
-#[derive(JSTraceable, Copy, Clone, PartialEq, Debug)]
+#[derive(JSTraceable, Copy, Clone, PartialEq, Debug, HeapSizeOf)]
 pub enum CharacterDataTypeId {
     Comment,
     Text,

components/script/dom/document.rs

@@ -110,6 +110,7 @@ pub enum IsHTMLDocument {
 
 // https://dom.spec.whatwg.org/#document
 #[dom_struct]
+#[derive(HeapSizeOf)]
 pub struct Document {
     node: Node,
     window: JS<Window>,
@@ -144,6 +145,7 @@ pub struct Document {
     animation_frame_ident: Cell<i32>,
     /// https://html.spec.whatwg.org/multipage/#list-of-animation-frame-callbacks
     /// List of animation frame callbacks
+    #[ignore_heap_size_of = "closures are hard"]
     animation_frame_list: RefCell<HashMap<i32, Box<Fn(f64)>>>,
     /// Tracks all outstanding loads related to this document.
     loader: DOMRefCell<DocumentLoader>,

components/script/dom/element.rs

@@ -120,7 +120,7 @@ impl PartialEq for Element {
     }
 }
 
-#[derive(JSTraceable, Copy, Clone, PartialEq, Debug)]
+#[derive(JSTraceable, Copy, Clone, PartialEq, Debug, HeapSizeOf)]
 pub enum ElementTypeId {
     HTMLElement(HTMLElementTypeId),
     Element,

components/script/dom/eventtarget.rs

@@ -20,6 +20,7 @@ use js::jsapi::{CompileFunction, JS_GetFunctionObject};
 use js::jsapi::{JSContext, RootedFunction, HandleObject};
 use js::jsapi::{JSAutoCompartment, JSAutoRequest};
 use js::rust::{AutoObjectVectorWrapper, CompileOptionsWrapper};
+use util::mem::HeapSizeOf;
 use util::str::DOMString;
 
 use fnv::FnvHasher;
@@ -36,13 +37,14 @@ use url::Url;
 
 use std::collections::HashMap;
 
-#[derive(JSTraceable, Copy, Clone, PartialEq)]
+#[derive(JSTraceable, Copy, Clone, PartialEq, HeapSizeOf)]
 pub enum ListenerPhase {
     Capturing,
     Bubbling,
 }
 
 #[derive(JSTraceable, Copy, Clone)]
+#[derive(HeapSizeOf)]
 pub enum EventTargetTypeId {
     Node(NodeTypeId),
     WebSocket,
@@ -95,6 +97,13 @@ pub enum EventListenerType {
     Inline(Rc<EventListener>),
 }
 
+impl HeapSizeOf for EventListenerType {
+    fn heap_size_of_children(&self) -> usize {
+        // FIXME: Rc<T> isn't HeapSizeOf and we can't ignore it due to #6870 and #6871
+        0
+    }
+}
+
 impl EventListenerType {
     fn get_listener(&self) -> Rc<EventListener> {
         match *self {
@@ -104,7 +113,7 @@ impl EventListenerType {
     }
 }
 
-#[derive(JSTraceable, Clone, PartialEq)]
+#[derive(JSTraceable, Clone, PartialEq, HeapSizeOf)]
 #[privatize]
 pub struct EventListenerEntry {
     phase: ListenerPhase,
@@ -112,6 +121,7 @@ pub struct EventListenerEntry {
 }
 
 #[dom_struct]
+#[derive(HeapSizeOf)]
 pub struct EventTarget {
     reflector_: Reflector,
     type_id: EventTargetTypeId,

components/script/dom/htmlelement.rs

@@ -366,7 +366,7 @@ impl<'a> VirtualMethods for &'a HTMLElement {
     }
 }
 
-#[derive(JSTraceable, Copy, Clone, Debug)]
+#[derive(JSTraceable, Copy, Clone, Debug, HeapSizeOf)]
 pub enum HTMLElementTypeId {
     HTMLElement,
 

components/script/dom/htmlmediaelement.rs

@@ -41,7 +41,7 @@ impl HTMLMediaElement {
     }
 }
 
-#[derive(JSTraceable, Copy, Clone, Debug)]
+#[derive(JSTraceable, Copy, Clone, Debug, HeapSizeOf)]
 pub enum HTMLMediaElementTypeId {
     HTMLAudioElement = 0,
     HTMLVideoElement = 1,

components/script/dom/htmltablecellelement.rs

@@ -22,7 +22,7 @@ use std::cmp::max;
 
 const DEFAULT_COLSPAN: u32 = 1;
 
-#[derive(JSTraceable, Copy, Clone, Debug)]
+#[derive(JSTraceable, Copy, Clone, Debug, HeapSizeOf)]
 pub enum HTMLTableCellElementTypeId {
     HTMLTableDataCellElement = 0,
     HTMLTableHeaderCellElement = 1,

components/script/dom/node.rs

@@ -78,6 +78,7 @@ use string_cache::{Atom, Namespace, QualName};
 
 /// An HTML node.
 #[dom_struct]
+#[derive(HeapSizeOf)]
 pub struct Node {
     /// The JavaScript reflector for this node.
     eventtarget: EventTarget,
@@ -135,7 +136,7 @@ impl NodeDerived for EventTarget {
 
 bitflags! {
     #[doc = "Flags for node items."]
-    #[derive(JSTraceable)]
+    #[derive(JSTraceable, HeapSizeOf)]
     flags NodeFlags: u16 {
         #[doc = "Specifies whether this node is in a document."]
         const IS_IN_DOC = 0x01,
@@ -206,20 +207,25 @@ enum SuppressObserver {
 }
 
 /// Layout data that is shared between the script and layout tasks.
+#[derive(HeapSizeOf)]
 pub struct SharedLayoutData {
     /// The results of CSS styling for this node.
     pub style: Option<Arc<ComputedValues>>,
 }
 
 /// Encapsulates the abstract layout data.
+#[allow(raw_pointer_derive)]
+#[derive(HeapSizeOf)]
 pub struct LayoutData {
     _shared_data: SharedLayoutData,
+    #[ignore_heap_size_of = "TODO(#6910) Box value that should be counted but the type lives in layout"]
     _data: NonZero<*const ()>,
 }
 
 #[allow(unsafe_code)]
 unsafe impl Send for LayoutData {}
 
+#[derive(HeapSizeOf)]
 pub struct LayoutDataRef {
     data_cell: RefCell<Option<LayoutData>>,
 }
@@ -274,6 +280,7 @@ impl LayoutDataRef {
 
 /// The different types of nodes.
 #[derive(JSTraceable, Copy, Clone, PartialEq, Debug)]
+#[derive(HeapSizeOf)]
 pub enum NodeTypeId {
     CharacterData(CharacterDataTypeId),
     DocumentType,

components/script/dom/window.rs

@@ -8,7 +8,7 @@ use dom::bindings::codegen::Bindings::EventHandlerBinding::{OnErrorEventHandlerN
 use dom::bindings::codegen::Bindings::DocumentBinding::DocumentMethods;
 use dom::bindings::codegen::Bindings::FunctionBinding::Function;
 use dom::bindings::codegen::Bindings::WindowBinding::{self, WindowMethods, FrameRequestCallback};
-use dom::bindings::codegen::InheritTypes::{NodeCast, ElementCast, EventTargetCast};
+use dom::bindings::codegen::InheritTypes::{NodeCast, ElementCast, EventTargetCast, WindowDerived};
 use dom::bindings::global::global_object_for_js_object;
 use dom::bindings::error::{report_pending_exception, Fallible};
 use dom::bindings::error::Error::InvalidCharacter;
@@ -81,7 +81,7 @@ use std::sync::mpsc::{channel, Receiver};
 use time;
 
 /// Current state of the window object
-#[derive(JSTraceable, Copy, Clone, Debug, PartialEq)]
+#[derive(JSTraceable, Copy, Clone, Debug, PartialEq, HeapSizeOf)]
 enum WindowState {
     Alive,
     Zombie,     // Pipeline is closed, but the window hasn't been GCed yet.
@@ -106,15 +106,21 @@ pub enum ReflowReason {
 }
 
 #[dom_struct]
+#[derive(HeapSizeOf)]
 pub struct Window {
     eventtarget: EventTarget,
+    #[ignore_heap_size_of = "trait objects are hard"]
     script_chan: Box<ScriptChan+Send>,
+    #[ignore_heap_size_of = "channels are hard"]
     control_chan: ScriptControlChan,
     console: MutNullableHeap<JS<Console>>,
     crypto: MutNullableHeap<JS<Crypto>>,
     navigator: MutNullableHeap<JS<Navigator>>,
+    #[ignore_heap_size_of = "channels are hard"]
     image_cache_task: ImageCacheTask,
+    #[ignore_heap_size_of = "channels are hard"]
     image_cache_chan: ImageCacheChan,
+    #[ignore_heap_size_of = "TODO(#6911) newtypes containing unmeasurable types are hard"]
     compositor: DOMRefCell<ScriptListener>,
     browsing_context: DOMRefCell<Option<BrowsingContext>>,
     page: Rc<Page>,
@@ -129,13 +135,17 @@ pub struct Window {
     next_worker_id: Cell<WorkerId>,
 
     /// For sending messages to the memory profiler.
+    #[ignore_heap_size_of = "channels are hard"]
     mem_profiler_chan: mem::ProfilerChan,
 
     /// For providing instructions to an optional devtools server.
+    #[ignore_heap_size_of = "channels are hard"]
     devtools_chan: Option<IpcSender<ScriptToDevtoolsControlMsg>>,
     /// For sending timeline markers. Will be ignored if
     /// no devtools server
+    #[ignore_heap_size_of = "TODO(#6909) need to measure HashSet"]
     devtools_markers: RefCell<HashSet<TimelineMarkerType>>,
+    #[ignore_heap_size_of = "channels are hard"]
     devtools_marker_sender: RefCell<Option<IpcSender<TimelineMarker>>>,
 
     /// A flag to indicate whether the developer tools have requested live updates of
@@ -160,27 +170,34 @@ pub struct Window {
     dom_static: GlobalStaticData,
 
     /// The JavaScript runtime.
+    #[ignore_heap_size_of = "Rc<T> is hard"]
     js_runtime: DOMRefCell<Option<Rc<Runtime>>>,
 
     /// A handle for communicating messages to the layout task.
+    #[ignore_heap_size_of = "channels are hard"]
     layout_chan: LayoutChan,
 
     /// A handle to perform RPC calls into the layout, quickly.
+    #[ignore_heap_size_of = "trait objects are hard"]
     layout_rpc: Box<LayoutRPC+'static>,
 
     /// The port that we will use to join layout. If this is `None`, then layout is not running.
+    #[ignore_heap_size_of = "channels are hard"]
     layout_join_port: DOMRefCell<Option<Receiver<()>>>,
 
     /// The current size of the window, in pixels.
     window_size: Cell<Option<WindowSizeData>>,
 
     /// Associated resource task for use by DOM objects like XMLHttpRequest
+    #[ignore_heap_size_of = "channels are hard"]
     resource_task: Arc<ResourceTask>,
 
     /// A handle for communicating messages to the storage task.
+    #[ignore_heap_size_of = "channels are hard"]
     storage_task: StorageTask,
 
     /// A handle for communicating messages to the constellation task.
+    #[ignore_heap_size_of = "channels are hard"]
     constellation_chan: ConstellationChan,
 
     /// Pending scroll to fragment event, if any
@@ -194,6 +211,7 @@ pub struct Window {
     pending_reflow_count: Cell<u32>,
 
     /// A channel for communicating results of async scripts back to the webdriver server
+    #[ignore_heap_size_of = "channels are hard"]
     webdriver_script_chan: RefCell<Option<IpcSender<WebDriverJSResult>>>,
 
     /// The current state of the window object
@@ -1182,3 +1200,9 @@ fn debug_reflow_events(goal: &ReflowGoal, query_type: &ReflowQueryType, reason:
 
     println!("{}", debug_msg);
 }
+
+impl WindowDerived for EventTarget {
+    fn is_window(&self) -> bool {
+        self.type_id() == &EventTargetTypeId::Window
+    }
+}

components/script/dom/workerglobalscope.rs

@@ -37,7 +37,7 @@ use std::cell::Cell;
 use std::rc::Rc;
 use std::sync::mpsc::Receiver;
 
-#[derive(JSTraceable, Copy, Clone, PartialEq)]
+#[derive(JSTraceable, Copy, Clone, PartialEq, HeapSizeOf)]
 pub enum WorkerGlobalScopeTypeId {
     DedicatedGlobalScope,
 }

components/script/dom/xmlhttprequesteventtarget.rs

@@ -8,7 +8,7 @@ use dom::bindings::codegen::InheritTypes::EventTargetCast;
 use dom::bindings::codegen::InheritTypes::XMLHttpRequestEventTargetDerived;
 use dom::eventtarget::{EventTarget, EventTargetHelpers, EventTargetTypeId};
 
-#[derive(JSTraceable, Copy, Clone, PartialEq)]
+#[derive(JSTraceable, Copy, Clone, PartialEq, HeapSizeOf)]
 pub enum XMLHttpRequestEventTargetTypeId {
     XMLHttpRequest,
     XMLHttpRequestUpload,

components/script/lib.rs

@@ -84,6 +84,7 @@ pub mod dom;
 pub mod parse;
 
 pub mod layout_interface;
+mod mem;
 mod network_listener;
 pub mod page;
 pub mod script_task;

components/script/mem.rs

@@ -0,0 +1,36 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//! Routines for handling measuring the memory usage of arbitrary DOM nodes.
+
+use dom::bindings::codegen::InheritTypes::{DocumentCast, WindowCast, CharacterDataCast, NodeCast};
+use dom::eventtarget::{EventTarget, EventTargetTypeId};
+use dom::node::NodeTypeId;
+use libc;
+use util::mem::{HeapSizeOf, heap_size_of};
+
+// This is equivalent to measuring a Box<T>, except that DOM objects lose their
+// associated box in order to stash their pointers in a reserved slot of their
+// JS reflector. It is assumed that the caller passes a pointer to the most-derived
+// type that this pointer represents, or the actual heap usage of the pointee will
+// be under-reported.
+fn heap_size_of_self_and_children<T: HeapSizeOf>(obj: &T) -> usize {
+    heap_size_of(obj as *const T as *const libc::c_void) + obj.heap_size_of_children()
+}
+
+pub fn heap_size_of_eventtarget(target: &EventTarget) -> usize {
+    //TODO: add more specific matches for concrete element types as derive(HeapSizeOf) is
+    //      added to each one.
+    match target.type_id() {
+        &EventTargetTypeId::Window =>
+            heap_size_of_self_and_children(WindowCast::to_ref(target).unwrap()),
+        &EventTargetTypeId::Node(NodeTypeId::CharacterData(_)) =>
+            heap_size_of_self_and_children(CharacterDataCast::to_ref(target).unwrap()),
+        &EventTargetTypeId::Node(NodeTypeId::Document) =>
+            heap_size_of_self_and_children(DocumentCast::to_ref(target).unwrap()),
+        &EventTargetTypeId::Node(_) =>
+            heap_size_of_self_and_children(NodeCast::to_ref(target).unwrap()),
+        _ => 0,
+    }
+}

components/script/page.rs

@@ -13,7 +13,7 @@ use std::cell::Cell;
 use std::rc::Rc;
 
 /// Encapsulates a handle to a frame in a frame tree.
-#[derive(JSTraceable)]
+#[derive(JSTraceable, HeapSizeOf)]
 #[allow(unrooted_must_root)] // FIXME(#6687) this is wrong
 pub struct Page {
     /// Pipeline id associated with this page.
@@ -127,7 +127,7 @@ impl Page {
 }
 
 /// Information for one frame in the browsing context.
-#[derive(JSTraceable)]
+#[derive(JSTraceable, HeapSizeOf)]
 #[must_root]
 pub struct Frame {
     /// The document for this frame.

components/script/script_task.rs

@@ -46,6 +46,7 @@ use dom::worker::TrustedWorkerAddress;
 use parse::html::{ParseContext, parse_html};
 use layout_interface::{self, NewLayoutTaskInfo, ScriptLayoutChan, LayoutChan, ReflowGoal};
 use layout_interface::{ReflowQueryType};
+use mem::heap_size_of_eventtarget;
 use network_listener::NetworkListener;
 use page::{Page, IterablePage, Frame};
 use timers::TimerId;
@@ -1104,11 +1105,28 @@ impl ScriptTask {
 
     fn collect_reports(&self, reports_chan: ReportsChan) {
         let mut urls = vec![];
+        let mut dom_tree_size = 0;
+        let mut reports = vec![];
         for it_page in self.root_page().iter() {
-            urls.push(it_page.document().url().serialize());
+            let current_url = it_page.document().url().serialize();
+            urls.push(current_url.clone());
+
+            for child in NodeCast::from_ref(&*it_page.document()).traverse_preorder() {
+                let target = EventTargetCast::from_ref(&*child);
+                dom_tree_size += heap_size_of_eventtarget(target);
+            }
+            let window = it_page.window();
+            let target = EventTargetCast::from_ref(&*window);
+            dom_tree_size += heap_size_of_eventtarget(target);
+
+            reports.push(Report {
+                path: path![format!("url({})", current_url), "dom-tree"],
+                kind: ReportKind::ExplicitJemallocHeapSize,
+                size: dom_tree_size,
+            })
         }
         let path_seg = format!("url({})", urls.join(", "));
-        let reports = ScriptTask::get_reports(self.get_cx(), path_seg);
+        reports.extend(ScriptTask::get_reports(self.get_cx(), path_seg));
         reports_chan.send(reports);
     }
 

components/script/timers.rs

@@ -13,6 +13,7 @@ use dom::window::ScriptHelpers;
 use script_task::{ScriptChan, ScriptMsg, TimerSource};
 use horribly_inefficient_timers;
 
+use util::mem::HeapSizeOf;
 use util::task::spawn_named;
 use util::str::DOMString;
 
@@ -29,14 +30,15 @@ use std::hash::{Hash, Hasher};
 use std::rc::Rc;
 use std::default::Default;
 
-#[derive(JSTraceable, PartialEq, Eq, Copy, Clone)]
+#[derive(JSTraceable, PartialEq, Eq, Copy, Clone, HeapSizeOf)]
 pub struct TimerId(i32);
 
-#[derive(JSTraceable)]
+#[derive(JSTraceable, HeapSizeOf)]
 #[privatize]
 struct TimerHandle {
     handle: TimerId,
     data: TimerData,
+    #[ignore_heap_size_of = "channels are hard"]
     control_chan: Option<Sender<TimerControlMsg>>,
 }
 
@@ -46,6 +48,13 @@ pub enum TimerCallback {
     FunctionTimerCallback(Rc<Function>)
 }
 
+impl HeapSizeOf for TimerCallback {
+    fn heap_size_of_children(&self) -> usize {
+        // FIXME: Rc<T> isn't HeapSizeOf and we can't ignore it due to #6870 and #6871
+        0
+    }
+}
+
 impl Hash for TimerId {
     fn hash<H: Hasher>(&self, state: &mut H) {
         let TimerId(id) = *self;
@@ -65,7 +74,7 @@ impl TimerHandle {
     }
 }
 
-#[derive(JSTraceable)]
+#[derive(JSTraceable, HeapSizeOf)]
 #[privatize]
 pub struct TimerManager {
     active_timers: DOMRefCell<HashMap<TimerId, TimerHandle>>,
@@ -82,7 +91,7 @@ impl Drop for TimerManager {
 }
 
 // Enum allowing more descriptive values for the is_interval field
-#[derive(JSTraceable, PartialEq, Copy, Clone)]
+#[derive(JSTraceable, PartialEq, Copy, Clone, HeapSizeOf)]
 pub enum IsInterval {
     Interval,
     NonInterval,
@@ -100,7 +109,7 @@ pub enum TimerControlMsg {
 // (ie. function value to invoke and all arguments to pass
 //      to the function when calling it)
 // TODO: Handle rooting during fire_timer when movable GC is turned on
-#[derive(JSTraceable)]
+#[derive(JSTraceable, HeapSizeOf)]
 #[privatize]
 struct TimerData {
     is_interval: IsInterval,