Add a `profile_traits` crate to reduce compile times.

A rebuild after touching components/profile/mem.rs now takes 48 seconds (and
only rebuilds `profile` and `servo`) which is much lower than it used to be.
In comparison, a rebuild after touching components/profile_traits/mem.rs takes
294 seconds and rebuilds many more crates.

This change also removes some unnecessary crate dependencies in `net` and
`net_traits`.

37 files changed, 269 insertions, 225 deletions

diff --git a/components/compositing/Cargo.toml b/components/compositing/Cargo.toml
index fcc129e2ccc..c14652b1662 100644
--- a/components/compositing/Cargo.toml
+++ b/components/compositing/Cargo.toml
@@ -22,8 +22,8 @@ path = "../msg"
 [dependencies.net]
 path = "../net"
 
-[dependencies.profile]
-path = "../profile"
+[dependencies.profile_traits]
+path = "../profile_traits"
 
 [dependencies.net_traits]
 path = "../net_traits"
diff --git a/components/compositing/compositor.rs b/components/compositing/compositor.rs
index 727760e57ed..3c9bbc6b8fa 100644
--- a/components/compositing/compositor.rs
+++ b/components/compositing/compositor.rs
@@ -32,8 +32,8 @@ use msg::constellation_msg::{ConstellationChan, NavigationDirection};
 use msg::constellation_msg::{Key, KeyModifiers, KeyState, LoadData};
 use msg::constellation_msg::{PipelineId, WindowSizeData};
 use png;
-use profile::mem;
-use profile::time::{self, ProfilerCategory, profile};
+use profile_traits::mem;
+use profile_traits::time::{self, ProfilerCategory, profile};
 use script_traits::{ConstellationControlMsg, ScriptControlChan};
 use std::cmp;
 use std::collections::HashMap;
diff --git a/components/compositing/compositor_task.rs b/components/compositing/compositor_task.rs
index 69e5ef4f17b..acafbbc8f9b 100644
--- a/components/compositing/compositor_task.rs
+++ b/components/compositing/compositor_task.rs
@@ -21,8 +21,8 @@ use msg::compositor_msg::{Epoch, LayerId, LayerMetadata, ReadyState};
 use msg::compositor_msg::{PaintListener, PaintState, ScriptListener, ScrollPolicy};
 use msg::constellation_msg::{ConstellationChan, PipelineId};
 use msg::constellation_msg::{Key, KeyState, KeyModifiers};
-use profile::mem;
-use profile::time;
+use profile_traits::mem;
+use profile_traits::time;
 use std::sync::mpsc::{channel, Sender, Receiver};
 use std::fmt::{Error, Formatter, Debug};
 use std::rc::Rc;
diff --git a/components/compositing/constellation.rs b/components/compositing/constellation.rs
index 7ad95f89b90..a9271bc0cfd 100644
--- a/components/compositing/constellation.rs
+++ b/components/compositing/constellation.rs
@@ -23,8 +23,8 @@ use msg::constellation_msg::{self, ConstellationChan, Failure};
 use net_traits::{self, ResourceTask};
 use net_traits::image_cache_task::ImageCacheTask;
 use net_traits::storage_task::{StorageTask, StorageTaskMsg};
-use profile::mem;
-use profile::time;
+use profile_traits::mem;
+use profile_traits::time;
 use script_traits::{CompositorEvent, ConstellationControlMsg};
 use script_traits::{ScriptControlChan, ScriptTaskFactory};
 use std::borrow::ToOwned;
diff --git a/components/compositing/headless.rs b/components/compositing/headless.rs
index 46f8351ba21..e0c5c1fad1c 100644
--- a/components/compositing/headless.rs
+++ b/components/compositing/headless.rs
@@ -9,8 +9,8 @@ use geom::scale_factor::ScaleFactor;
 use geom::size::TypedSize2D;
 use msg::constellation_msg::Msg as ConstellationMsg;
 use msg::constellation_msg::{ConstellationChan, WindowSizeData};
-use profile::mem;
-use profile::time;
+use profile_traits::mem;
+use profile_traits::time;
 
 /// Starts the compositor, which listens for messages on the specified port.
 ///
diff --git a/components/compositing/lib.rs b/components/compositing/lib.rs
index 7b8d49348c3..09a7eae774a 100644
--- a/components/compositing/lib.rs
+++ b/components/compositing/lib.rs
@@ -22,7 +22,7 @@ extern crate png;
 extern crate script_traits;
 extern crate msg;
 extern crate net;
-extern crate profile;
+extern crate profile_traits;
 extern crate net_traits;
 #[macro_use]
 extern crate util;
diff --git a/components/compositing/pipeline.rs b/components/compositing/pipeline.rs
index 3c96524b18b..06d85a2ca2a 100644
--- a/components/compositing/pipeline.rs
+++ b/components/compositing/pipeline.rs
@@ -16,8 +16,8 @@ use gfx::font_cache_task::FontCacheTask;
 use layers::geometry::DevicePixel;
 use msg::constellation_msg::{ConstellationChan, Failure, FrameId, PipelineId, SubpageId};
 use msg::constellation_msg::{LoadData, WindowSizeData, PipelineExitType, MozBrowserEvent};
-use profile::mem;
-use profile::time;
+use profile_traits::mem;
+use profile_traits::time;
 use net_traits::ResourceTask;
 use net_traits::image_cache_task::ImageCacheTask;
 use net_traits::storage_task::StorageTask;
diff --git a/components/gfx/Cargo.toml b/components/gfx/Cargo.toml
index c78bda489d1..aaefa6c900c 100644
--- a/components/gfx/Cargo.toml
+++ b/components/gfx/Cargo.toml
@@ -20,8 +20,8 @@ path = "../util"
 [dependencies.msg]
 path = "../msg"
 
-[dependencies.profile]
-path = "../profile"
+[dependencies.profile_traits]
+path = "../profile_traits"
 
 [dependencies.style]
 path = "../style"
diff --git a/components/gfx/lib.rs b/components/gfx/lib.rs
index 3e59c8305a6..d44d52b5410 100644
--- a/components/gfx/lib.rs
+++ b/components/gfx/lib.rs
@@ -26,7 +26,7 @@ extern crate layers;
 extern crate libc;
 extern crate stb_image;
 extern crate png;
-extern crate profile;
+extern crate profile_traits;
 extern crate script_traits;
 extern crate "rustc-serialize" as rustc_serialize;
 extern crate unicode;
diff --git a/components/gfx/paint_task.rs b/components/gfx/paint_task.rs
index a97487db92d..ba07f89bfa4 100644
--- a/components/gfx/paint_task.rs
+++ b/components/gfx/paint_task.rs
@@ -25,7 +25,7 @@ use msg::compositor_msg::{LayerMetadata, PaintListener, ScrollPolicy};
 use msg::constellation_msg::Msg as ConstellationMsg;
 use msg::constellation_msg::{ConstellationChan, Failure, PipelineId};
 use msg::constellation_msg::PipelineExitType;
-use profile::time::{self, profile};
+use profile_traits::time::{self, profile};
 use skia::SkiaGrGLNativeContextRef;
 use std::borrow::ToOwned;
 use std::mem;
diff --git a/components/layout/Cargo.toml b/components/layout/Cargo.toml
index 62a0e16ee65..27ca46a7f49 100644
--- a/components/layout/Cargo.toml
+++ b/components/layout/Cargo.toml
@@ -37,8 +37,8 @@ path = "../plugins"
 [dependencies.net_traits]
 path = "../net_traits"
 
-[dependencies.profile]
-path = "../profile"
+[dependencies.profile_traits]
+path = "../profile_traits"
 
 [dependencies.util]
 path = "../util"
diff --git a/components/layout/layout_task.rs b/components/layout/layout_task.rs
index 6166b95f73b..dbcf03df1b0 100644
--- a/components/layout/layout_task.rs
+++ b/components/layout/layout_task.rs
@@ -42,9 +42,9 @@ use log;
 use msg::compositor_msg::ScrollPolicy;
 use msg::constellation_msg::Msg as ConstellationMsg;
 use msg::constellation_msg::{ConstellationChan, Failure, PipelineExitType, PipelineId};
-use profile::mem::{self, Report, ReportsChan};
-use profile::time::{self, ProfilerMetadata, profile};
-use profile::time::{TimerMetadataFrameType, TimerMetadataReflowType};
+use profile_traits::mem::{self, Report, ReportsChan};
+use profile_traits::time::{self, ProfilerMetadata, profile};
+use profile_traits::time::{TimerMetadataFrameType, TimerMetadataReflowType};
 use net_traits::{load_bytes_iter, ResourceTask};
 use net_traits::image_cache_task::{ImageCacheTask, ImageCacheResult, ImageCacheChan};
 use script::dom::bindings::js::LayoutJS;
diff --git a/components/layout/lib.rs b/components/layout/lib.rs
index 844689f0534..876d8f7c425 100644
--- a/components/layout/lib.rs
+++ b/components/layout/lib.rs
@@ -32,7 +32,7 @@ extern crate bitflags;
 extern crate "plugins" as servo_plugins;
 extern crate net_traits;
 #[macro_use]
-extern crate profile;
+extern crate profile_traits;
 
 #[macro_use]
 extern crate util;
diff --git a/components/layout/parallel.rs b/components/layout/parallel.rs
index 6699e44d487..5d61e11a3d4 100644
--- a/components/layout/parallel.rs
+++ b/components/layout/parallel.rs
@@ -20,7 +20,7 @@ use wrapper::{layout_node_to_unsafe_layout_node, layout_node_from_unsafe_layout_
 use wrapper::{PostorderNodeMutTraversal, UnsafeLayoutNode};
 use wrapper::{PreorderDomTraversal, PostorderDomTraversal};
 
-use profile::time::{self, ProfilerMetadata, profile};
+use profile_traits::time::{self, ProfilerMetadata, profile};
 use std::mem;
 use std::ptr;
 use std::sync::atomic::{AtomicIsize, Ordering};
diff --git a/components/layout_traits/Cargo.toml b/components/layout_traits/Cargo.toml
index 02df09b7f2b..17d706eeca3 100644
--- a/components/layout_traits/Cargo.toml
+++ b/components/layout_traits/Cargo.toml
@@ -19,8 +19,8 @@ path = "../msg"
 [dependencies.net_traits]
 path = "../net_traits"
 
-[dependencies.profile]
-path = "../profile"
+[dependencies.profile_traits]
+path = "../profile_traits"
 
 [dependencies.util]
 path = "../util"
diff --git a/components/layout_traits/lib.rs b/components/layout_traits/lib.rs
index 406730f65d7..f37cfa194bb 100644
--- a/components/layout_traits/lib.rs
+++ b/components/layout_traits/lib.rs
@@ -5,7 +5,7 @@
 extern crate gfx;
 extern crate script_traits;
 extern crate msg;
-extern crate profile;
+extern crate profile_traits;
 extern crate net_traits;
 extern crate url;
 extern crate util;
@@ -18,8 +18,8 @@ extern crate util;
 use gfx::font_cache_task::FontCacheTask;
 use gfx::paint_task::PaintChan;
 use msg::constellation_msg::{ConstellationChan, Failure, PipelineId, PipelineExitType};
-use profile::mem;
-use profile::time;
+use profile_traits::mem;
+use profile_traits::time;
 use net_traits::ResourceTask;
 use net_traits::image_cache_task::ImageCacheTask;
 use url::Url;
diff --git a/components/net/Cargo.toml b/components/net/Cargo.toml
index 2f33836598c..0548c6f00a9 100644
--- a/components/net/Cargo.toml
+++ b/components/net/Cargo.toml
@@ -7,9 +7,6 @@ authors = ["The Servo Project Developers"]
 name = "net"
 path = "lib.rs"
 
-[dependencies.profile]
-path = "../profile"
-
 [dependencies.net_traits]
 path = "../net_traits"
 
diff --git a/components/net/lib.rs b/components/net/lib.rs
index cdc6217b706..70f4a14db59 100644
--- a/components/net/lib.rs
+++ b/components/net/lib.rs
@@ -27,7 +27,6 @@ extern crate png;
 #[macro_use]
 extern crate log;
 extern crate openssl;
-extern crate profile;
 extern crate "rustc-serialize" as rustc_serialize;
 extern crate util;
 extern crate time;
diff --git a/components/net_traits/Cargo.toml b/components/net_traits/Cargo.toml
index f75b04eff49..bd336eb2a9c 100644
--- a/components/net_traits/Cargo.toml
+++ b/components/net_traits/Cargo.toml
@@ -13,9 +13,6 @@ git = "https://github.com/servo/rust-geom"
 [dependencies.png]
 git = "https://github.com/servo/rust-png"
 
-[dependencies.profile]
-path = "../profile"
-
 [dependencies.util]
 path = "../util"
 
diff --git a/components/net_traits/lib.rs b/components/net_traits/lib.rs
index 55cb27a0519..879643af266 100644
--- a/components/net_traits/lib.rs
+++ b/components/net_traits/lib.rs
@@ -12,7 +12,6 @@ extern crate hyper;
 #[macro_use]
 extern crate log;
 extern crate png;
-extern crate profile;
 extern crate stb_image;
 extern crate url;
 extern crate util;
diff --git a/components/profile/Cargo.toml b/components/profile/Cargo.toml
index de9fb13a597..dfb3a187e30 100644
--- a/components/profile/Cargo.toml
+++ b/components/profile/Cargo.toml
@@ -7,6 +7,9 @@ authors = ["The Servo Project Developers"]
 name = "profile"
 path = "lib.rs"
 
+[dependencies.profile_traits]
+path = "../profile_traits"
+
 [dependencies.task_info]
 path = "../../support/rust-task_info"
 
@@ -17,4 +20,3 @@ path = "../util"
 libc = "*"
 regex = "0.1.14"
 time = "0.1.12"
-url = "0.2.16"
diff --git a/components/profile/lib.rs b/components/profile/lib.rs
index 55a59065a4e..3d6e91e5dcc 100644
--- a/components/profile/lib.rs
+++ b/components/profile/lib.rs
@@ -16,13 +16,14 @@
 
 extern crate collections;
 extern crate libc;
+#[macro_use]
+extern crate profile_traits;
 #[cfg(target_os="linux")]
 extern crate regex;
 #[cfg(target_os="macos")]
 extern crate task_info;
 extern crate "time" as std_time;
 extern crate util;
-extern crate url;
 
 pub mod mem;
 pub mod time;
diff --git a/components/profile/mem.rs b/components/profile/mem.rs
index 522ebe896b4..bc8b84ac1bb 100644
--- a/components/profile/mem.rs
+++ b/components/profile/mem.rs
@@ -4,83 +4,16 @@
 
 //! Memory profiling functions.
 
+use profile_traits::mem::{ProfilerChan, ProfilerMsg, Reporter, ReportsChan};
 use self::system_reporter::SystemReporter;
 use std::borrow::ToOwned;
 use std::cmp::Ordering;
 use std::collections::HashMap;
 use std::old_io::timer::sleep;
-use std::sync::mpsc::{Sender, channel, Receiver};
+use std::sync::mpsc::{channel, Receiver};
 use std::time::duration::Duration;
 use util::task::spawn_named;
 
-#[derive(Clone)]
-pub struct ProfilerChan(pub Sender<ProfilerMsg>);
-
-impl ProfilerChan {
-    pub fn send(&self, msg: ProfilerMsg) {
-        let ProfilerChan(ref c) = *self;
-        c.send(msg).unwrap();
-    }
-}
-
-/// An easy way to build a path for a report.
-#[macro_export]
-macro_rules! path {
-    ($($x:expr),*) => {{
-        use std::borrow::ToOwned;
-        vec![$( $x.to_owned() ),*]
-    }}
-}
-
-/// A single memory-related measurement.
-pub struct Report {
-    /// The identifying path for this report.
-    pub path: Vec<String>,
-
-    /// The size, in bytes.
-    pub size: usize,
-}
-
-/// A channel through which memory reports can be sent.
-#[derive(Clone)]
-pub struct ReportsChan(pub Sender<Vec<Report>>);
-
-impl ReportsChan {
-    pub fn send(&self, report: Vec<Report>) {
-        let ReportsChan(ref c) = *self;
-        c.send(report).unwrap();
-    }
-}
-
-/// A memory reporter is capable of measuring some data structure of interest. Because it needs
-/// to be passed to and registered with the Profiler, it's typically a "small" (i.e. easily
-/// cloneable) value that provides access to a "large" data structure, e.g. a channel that can
-/// inject a request for measurements into the event queue associated with the "large" data
-/// structure.
-pub trait Reporter {
-    /// Collect one or more memory reports. Returns true on success, and false on failure.
-    fn collect_reports(&self, reports_chan: ReportsChan) -> bool;
-}
-
-/// Messages that can be sent to the memory profiler thread.
-pub enum ProfilerMsg {
-    /// Register a Reporter with the memory profiler. The String is only used to identify the
-    /// reporter so it can be unregistered later. The String must be distinct from that used by any
-    /// other registered reporter otherwise a panic will occur.
-    RegisterReporter(String, Box<Reporter + Send>),
-
-    /// Unregister a Reporter with the memory profiler. The String must match the name given when
-    /// the reporter was registered. If the String does not match the name of a registered reporter
-    /// a panic will occur.
-    UnregisterReporter(String),
-
-    /// Triggers printing of the memory profiling metrics.
-    Print,
-
-    /// Tells the memory profiler to shut down.
-    Exit,
-}
-
 pub struct Profiler {
     /// The port through which messages are received.
     pub port: Receiver<ProfilerMsg>,
@@ -363,11 +296,11 @@ impl ReportsForest {
 
 mod system_reporter {
     use libc::{c_char, c_int, c_void, size_t};
+    use profile_traits::mem::{Report, Reporter, ReportsChan};
     use std::borrow::ToOwned;
     use std::ffi::CString;
     use std::mem::size_of;
     use std::ptr::null_mut;
-    use super::{Report, Reporter, ReportsChan};
     #[cfg(target_os="macos")]
     use task_info::task_basic_info::{virtual_size, resident_size};
 
diff --git a/components/profile/time.rs b/components/profile/time.rs
index 8b85f4d8e7c..284853a5480 100644
--- a/components/profile/time.rs
+++ b/components/profile/time.rs
@@ -5,36 +5,18 @@
 //! Timing functions.
 
 use collections::BTreeMap;
+use profile_traits::time::{ProfilerCategory, ProfilerChan, ProfilerMsg, TimerMetadata};
 use std::borrow::ToOwned;
 use std::cmp::Ordering;
 use std::f64;
 use std::old_io::timer::sleep;
 use std::iter::AdditiveIterator;
 use std::num::Float;
-use std::sync::mpsc::{Sender, channel, Receiver};
+use std::sync::mpsc::{channel, Receiver};
 use std::time::duration::Duration;
 use std_time::precise_time_ns;
-use url::Url;
 use util::task::spawn_named;
 
-// front-end representation of the profiler used to communicate with the profiler
-#[derive(Clone)]
-pub struct ProfilerChan(pub Sender<ProfilerMsg>);
-
-impl ProfilerChan {
-    pub fn send(&self, msg: ProfilerMsg) {
-        let ProfilerChan(ref c) = *self;
-        c.send(msg).unwrap();
-    }
-}
-
-#[derive(PartialEq, Clone, PartialOrd, Eq, Ord)]
-pub struct TimerMetadata {
-    url:         String,
-    iframe:      bool,
-    incremental: bool,
-}
-
 pub trait Formattable {
     fn format(&self) -> String;
 }
@@ -60,38 +42,6 @@ impl Formattable for Option<TimerMetadata> {
     }
 }
 
-#[derive(Clone)]
-pub enum ProfilerMsg {
-    /// Normal message used for reporting time
-    Time((ProfilerCategory, Option<TimerMetadata>), f64),
-    /// Message used to force print the profiling metrics
-    Print,
-    /// Tells the profiler to shut down.
-    Exit,
-}
-
-#[repr(u32)]
-#[derive(PartialEq, Clone, PartialOrd, Eq, Ord)]
-pub enum ProfilerCategory {
-    Compositing,
-    LayoutPerform,
-    LayoutStyleRecalc,
-    LayoutRestyleDamagePropagation,
-    LayoutNonIncrementalReset,
-    LayoutSelectorMatch,
-    LayoutTreeBuilder,
-    LayoutDamagePropagate,
-    LayoutGeneratedContent,
-    LayoutMain,
-    LayoutParallelWarmup,
-    LayoutShaping,
-    LayoutDispListBuild,
-    PaintingPerTile,
-    PaintingPrepBuff,
-    Painting,
-    ImageDecoding,
-}
-
 impl Formattable for ProfilerCategory {
     // some categories are subcategories of LayoutPerformCategory
     // and should be printed to indicate this
@@ -254,41 +204,6 @@ impl Profiler {
     }
 }
 
-#[derive(Eq, PartialEq)]
-pub enum TimerMetadataFrameType {
-    RootWindow,
-    IFrame,
-}
-
-#[derive(Eq, PartialEq)]
-pub enum TimerMetadataReflowType {
-    Incremental,
-    FirstReflow,
-}
-
-pub type ProfilerMetadata<'a> = Option<(&'a Url, TimerMetadataFrameType, TimerMetadataReflowType)>;
-
-pub fn profile<T, F>(category: ProfilerCategory,
-                     meta: ProfilerMetadata,
-                     profiler_chan: ProfilerChan,
-                     callback: F)
-                  -> T
-    where F: FnOnce() -> T
-{
-    let start_time = precise_time_ns();
-    let val = callback();
-    let end_time = precise_time_ns();
-    let ms = (end_time - start_time) as f64 / 1000000f64;
-    let meta = meta.map(|(url, iframe, reflow_type)|
-        TimerMetadata {
-            url: url.serialize(),
-            iframe: iframe == TimerMetadataFrameType::IFrame,
-            incremental: reflow_type == TimerMetadataReflowType::Incremental,
-        });
-    profiler_chan.send(ProfilerMsg::Time((category, meta), ms));
-    return val;
-}
-
 pub fn time<T, F>(msg: &str, callback: F) -> T
     where F: Fn() -> T
 {
diff --git a/components/profile_traits/Cargo.toml b/components/profile_traits/Cargo.toml
new file mode 100644
index 00000000000..eb9da970c20
--- /dev/null
+++ b/components/profile_traits/Cargo.toml
@@ -0,0 +1,13 @@
+[package]
+name = "profile_traits"
+version = "0.0.1"
+authors = ["The Servo Project Developers"]
+
+[lib]
+name = "profile_traits"
+path = "lib.rs"
+
+[dependencies]
+time = "0.1.12"
+url = "0.2.16"
+
diff --git a/components/profile_traits/lib.rs b/components/profile_traits/lib.rs
new file mode 100644
index 00000000000..25dbb0b4c5b
--- /dev/null
+++ b/components/profile_traits/lib.rs
@@ -0,0 +1,6 @@
+/* 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/. */
+
+pub mod mem;
+pub mod time;
diff --git a/components/profile_traits/mem.rs b/components/profile_traits/mem.rs
new file mode 100644
index 00000000000..f31e6f73358
--- /dev/null
+++ b/components/profile_traits/mem.rs
@@ -0,0 +1,72 @@
+/* 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/. */
+
+use std::sync::mpsc::Sender;
+
+#[derive(Clone)]
+pub struct ProfilerChan(pub Sender<ProfilerMsg>);
+
+impl ProfilerChan {
+    pub fn send(&self, msg: ProfilerMsg) {
+        let ProfilerChan(ref c) = *self;
+        c.send(msg).unwrap();
+    }
+}
+
+/// A single memory-related measurement.
+pub struct Report {
+    /// The identifying path for this report.
+    pub path: Vec<String>,
+
+    /// The size, in bytes.
+    pub size: usize,
+}
+
+/// A channel through which memory reports can be sent.
+#[derive(Clone)]
+pub struct ReportsChan(pub Sender<Vec<Report>>);
+
+impl ReportsChan {
+    pub fn send(&self, report: Vec<Report>) {
+        let ReportsChan(ref c) = *self;
+        c.send(report).unwrap();
+    }
+}
+
+/// A memory reporter is capable of measuring some data structure of interest. Because it needs to
+/// be passed to and registered with the Profiler, it's typically a "small" (i.e. easily cloneable)
+/// value that provides access to a "large" data structure, e.g. a channel that can inject a
+/// request for measurements into the event queue associated with the "large" data structure.
+pub trait Reporter {
+    /// Collect one or more memory reports. Returns true on success, and false on failure.
+    fn collect_reports(&self, reports_chan: ReportsChan) -> bool;
+}
+
+/// An easy way to build a path for a report.
+#[macro_export]
+macro_rules! path {
+    ($($x:expr),*) => {{
+        use std::borrow::ToOwned;
+        vec![$( $x.to_owned() ),*]
+    }}
+}
+
+/// Messages that can be sent to the memory profiler thread.
+pub enum ProfilerMsg {
+    /// Register a Reporter with the memory profiler. The String is only used to identify the
+    /// reporter so it can be unregistered later. The String must be distinct from that used by any
+    /// other registered reporter otherwise a panic will occur.
+    RegisterReporter(String, Box<Reporter + Send>),
+
+    /// Unregister a Reporter with the memory profiler. The String must match the name given when
+    /// the reporter was registered. If the String does not match the name of a registered reporter
+    /// a panic will occur.
+    UnregisterReporter(String),
+
+    /// Triggers printing of the memory profiling metrics.
+    Print,
+
+    /// Tells the memory profiler to shut down.
+    Exit,
+}
diff --git a/components/profile_traits/time.rs b/components/profile_traits/time.rs
new file mode 100644
index 00000000000..5cd794072f9
--- /dev/null
+++ b/components/profile_traits/time.rs
@@ -0,0 +1,95 @@
+/* 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/. */
+
+extern crate "time" as std_time;
+extern crate url;
+
+use self::std_time::precise_time_ns;
+use self::url::Url;
+use std::sync::mpsc::Sender;
+
+#[derive(PartialEq, Clone, PartialOrd, Eq, Ord)]
+pub struct TimerMetadata {
+    pub url:         String,
+    pub iframe:      bool,
+    pub incremental: bool,
+}
+
+#[derive(Clone)]
+pub struct ProfilerChan(pub Sender<ProfilerMsg>);
+
+impl ProfilerChan {
+    pub fn send(&self, msg: ProfilerMsg) {
+        let ProfilerChan(ref c) = *self;
+        c.send(msg).unwrap();
+    }
+}
+
+#[derive(Clone)]
+pub enum ProfilerMsg {
+    /// Normal message used for reporting time
+    Time((ProfilerCategory, Option<TimerMetadata>), f64),
+    /// Message used to force print the profiling metrics
+    Print,
+    /// Tells the profiler to shut down.
+    Exit,
+}
+
+#[repr(u32)]
+#[derive(PartialEq, Clone, PartialOrd, Eq, Ord)]
+pub enum ProfilerCategory {
+    Compositing,
+    LayoutPerform,
+    LayoutStyleRecalc,
+    LayoutRestyleDamagePropagation,
+    LayoutNonIncrementalReset,
+    LayoutSelectorMatch,
+    LayoutTreeBuilder,
+    LayoutDamagePropagate,
+    LayoutGeneratedContent,
+    LayoutMain,
+    LayoutParallelWarmup,
+    LayoutShaping,
+    LayoutDispListBuild,
+    PaintingPerTile,
+    PaintingPrepBuff,
+    Painting,
+    ImageDecoding,
+}
+
+#[derive(Eq, PartialEq)]
+pub enum TimerMetadataFrameType {
+    RootWindow,
+    IFrame,
+}
+
+#[derive(Eq, PartialEq)]
+pub enum TimerMetadataReflowType {
+    Incremental,
+    FirstReflow,
+}
+
+pub type ProfilerMetadata<'a> =
+    Option<(&'a Url, TimerMetadataFrameType, TimerMetadataReflowType)>;
+
+pub fn profile<T, F>(category: ProfilerCategory,
+                     meta: ProfilerMetadata,
+                     profiler_chan: ProfilerChan,
+                     callback: F)
+                  -> T
+    where F: FnOnce() -> T
+{
+    let start_time = precise_time_ns();
+    let val = callback();
+    let end_time = precise_time_ns();
+    let ms = (end_time - start_time) as f64 / 1000000f64;
+    let meta = meta.map(|(url, iframe, reflow_type)|
+        TimerMetadata {
+            url: url.serialize(),
+            iframe: iframe == TimerMetadataFrameType::IFrame,
+            incremental: reflow_type == TimerMetadataReflowType::Incremental,
+        });
+    profiler_chan.send(ProfilerMsg::Time((category, meta), ms));
+    return val;
+}
diff --git a/components/script/Cargo.toml b/components/script/Cargo.toml
index 50607cabefe..634c3e46d09 100644
--- a/components/script/Cargo.toml
+++ b/components/script/Cargo.toml
@@ -24,8 +24,8 @@ path = "../msg"
 [dependencies.net_traits]
 path = "../net_traits"
 
-[dependencies.profile]
-path = "../profile"
+[dependencies.profile_traits]
+path = "../profile_traits"
 
 [dependencies.script_traits]
 path = "../script_traits"
diff --git a/components/script/layout_interface.rs b/components/script/layout_interface.rs
index 4859c075058..05046c3e564 100644
--- a/components/script/layout_interface.rs
+++ b/components/script/layout_interface.rs
@@ -12,7 +12,7 @@ use geom::point::Point2D;
 use geom::rect::Rect;
 use libc::uintptr_t;
 use msg::constellation_msg::{PipelineExitType, WindowSizeData};
-use profile::mem::{Reporter, ReportsChan};
+use profile_traits::mem::{Reporter, ReportsChan};
 use script_traits::{ScriptControlChan, OpaqueScriptLayoutChannel, UntrustedNodeAddress};
 use std::any::Any;
 use std::sync::mpsc::{channel, Receiver, Sender};
diff --git a/components/script/lib.rs b/components/script/lib.rs
index 5c2e522f5d4..879216a2e27 100644
--- a/components/script/lib.rs
+++ b/components/script/lib.rs
@@ -43,7 +43,7 @@ extern crate png;
 extern crate "rustc-serialize" as rustc_serialize;
 extern crate time;
 extern crate canvas;
-extern crate profile;
+extern crate profile_traits;
 extern crate script_traits;
 extern crate selectors;
 extern crate util;
diff --git a/components/servo/Cargo.lock b/components/servo/Cargo.lock
index 5fdb4195f71..3adac4b1aa8 100644
--- a/components/servo/Cargo.lock
+++ b/components/servo/Cargo.lock
@@ -17,6 +17,7 @@ dependencies = [
  "net_traits 0.0.1",
  "png 0.1.0 (git+https://github.com/servo/rust-png)",
  "profile 0.0.1",
+ "profile_traits 0.0.1",
  "script 0.0.1",
  "script_tests 0.0.1",
  "style_tests 0.0.1",
@@ -121,7 +122,7 @@ dependencies = [
  "net 0.0.1",
  "net_traits 0.0.1",
  "png 0.1.0 (git+https://github.com/servo/rust-png)",
- "profile 0.0.1",
+ "profile_traits 0.0.1",
  "script_traits 0.0.1",
  "time 0.1.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -348,7 +349,7 @@ dependencies = [
  "net_traits 0.0.1",
  "plugins 0.0.1",
  "png 0.1.0 (git+https://github.com/servo/rust-png)",
- "profile 0.0.1",
+ "profile_traits 0.0.1",
  "rustc-serialize 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "script_traits 0.0.1",
  "skia 0.0.20130412 (git+https://github.com/servo/skia?branch=upstream-2014-06-16)",
@@ -561,7 +562,7 @@ dependencies = [
  "net_traits 0.0.1",
  "plugins 0.0.1",
  "png 0.1.0 (git+https://github.com/servo/rust-png)",
- "profile 0.0.1",
+ "profile_traits 0.0.1",
  "rustc-serialize 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "script 0.0.1",
  "script_traits 0.0.1",
@@ -580,7 +581,7 @@ dependencies = [
  "gfx 0.0.1",
  "msg 0.0.1",
  "net_traits 0.0.1",
- "profile 0.0.1",
+ "profile_traits 0.0.1",
  "script_traits 0.0.1",
  "url 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "util 0.0.1",
@@ -674,7 +675,6 @@ dependencies = [
  "net_traits 0.0.1",
  "openssl 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "png 0.1.0 (git+https://github.com/servo/rust-png)",
- "profile 0.0.1",
  "regex 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex_macros 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -691,7 +691,6 @@ dependencies = [
  "hyper 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "net 0.0.1",
  "net_traits 0.0.1",
- "profile 0.0.1",
  "url 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "util 0.0.1",
 ]
@@ -703,7 +702,6 @@ dependencies = [
  "geom 0.1.0 (git+https://github.com/servo/rust-geom)",
  "hyper 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "png 0.1.0 (git+https://github.com/servo/rust-png)",
- "profile 0.0.1",
  "stb_image 0.1.0 (git+https://github.com/servo/rust-stb-image)",
  "url 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "util 0.0.1",
@@ -809,14 +807,22 @@ name = "profile"
 version = "0.0.1"
 dependencies = [
  "libc 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "profile_traits 0.0.1",
  "regex 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "task_info 0.0.1",
  "time 0.1.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "url 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "util 0.0.1",
 ]
 
 [[package]]
+name = "profile_traits"
+version = "0.0.1"
+dependencies = [
+ "time 0.1.19 (registry+https://github.com/rust-lang/crates.io-index)",
+ "url 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "rand"
 version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -862,7 +868,7 @@ dependencies = [
  "net_traits 0.0.1",
  "plugins 0.0.1",
  "png 0.1.0 (git+https://github.com/servo/rust-png)",
- "profile 0.0.1",
+ "profile_traits 0.0.1",
  "rustc-serialize 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "script_traits 0.0.1",
  "selectors 0.1.0 (git+https://github.com/servo/rust-selectors)",
diff --git a/components/servo/Cargo.toml b/components/servo/Cargo.toml
index 24ab504b303..2a57db1d9ee 100644
--- a/components/servo/Cargo.toml
+++ b/components/servo/Cargo.toml
@@ -67,6 +67,9 @@ path = "../msg"
 [dependencies.profile]
 path = "../profile"
 
+[dependencies.profile_traits]
+path = "../profile_traits"
+
 [dependencies.util]
 path = "../util"
 
diff --git a/components/servo/lib.rs b/components/servo/lib.rs
index 22ec02646ef..b7a45efa1de 100644
--- a/components/servo/lib.rs
+++ b/components/servo/lib.rs
@@ -26,6 +26,7 @@ extern crate net;
 extern crate net_traits;
 extern crate msg;
 extern crate profile;
+extern crate profile_traits;
 #[macro_use]
 extern crate util;
 extern crate script;
@@ -52,8 +53,10 @@ use net::resource_task::new_resource_task;
 use net_traits::storage_task::StorageTask;
 
 use gfx::font_cache_task::FontCacheTask;
-use profile::mem;
-use profile::time;
+use profile::mem as profile_mem;
+use profile::time as profile_time;
+use profile_traits::mem;
+use profile_traits::time;
 use util::opts;
 
 use std::rc::Rc;
@@ -92,8 +95,8 @@ impl Browser  {
         // to deliver the message.
         let (compositor_proxy, compositor_receiver) =
             WindowMethods::create_compositor_channel(&window);
-        let time_profiler_chan = time::Profiler::create(opts.time_profiler_period);
-        let mem_profiler_chan = mem::Profiler::create(opts.mem_profiler_period);
+        let time_profiler_chan = profile_time::Profiler::create(opts.time_profiler_period);
+        let mem_profiler_chan = profile_mem::Profiler::create(opts.mem_profiler_period);
         let devtools_chan = opts.devtools_port.map(|port| {
             devtools::start_server(port)
         });
diff --git a/ports/cef/Cargo.lock b/ports/cef/Cargo.lock
index ab2eb625afa..cecc03294f7 100644
--- a/ports/cef/Cargo.lock
+++ b/ports/cef/Cargo.lock
@@ -119,7 +119,7 @@ dependencies = [
  "net 0.0.1",
  "net_traits 0.0.1",
  "png 0.1.0 (git+https://github.com/servo/rust-png)",
- "profile 0.0.1",
+ "profile_traits 0.0.1",
  "script_traits 0.0.1",
  "time 0.1.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -346,7 +346,7 @@ dependencies = [
  "net_traits 0.0.1",
  "plugins 0.0.1",
  "png 0.1.0 (git+https://github.com/servo/rust-png)",
- "profile 0.0.1",
+ "profile_traits 0.0.1",
  "rustc-serialize 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "script_traits 0.0.1",
  "skia 0.0.20130412 (git+https://github.com/servo/skia?branch=upstream-2014-06-16)",
@@ -552,7 +552,7 @@ dependencies = [
  "net_traits 0.0.1",
  "plugins 0.0.1",
  "png 0.1.0 (git+https://github.com/servo/rust-png)",
- "profile 0.0.1",
+ "profile_traits 0.0.1",
  "rustc-serialize 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "script 0.0.1",
  "script_traits 0.0.1",
@@ -571,7 +571,7 @@ dependencies = [
  "gfx 0.0.1",
  "msg 0.0.1",
  "net_traits 0.0.1",
- "profile 0.0.1",
+ "profile_traits 0.0.1",
  "script_traits 0.0.1",
  "url 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "util 0.0.1",
@@ -665,7 +665,6 @@ dependencies = [
  "net_traits 0.0.1",
  "openssl 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "png 0.1.0 (git+https://github.com/servo/rust-png)",
- "profile 0.0.1",
  "regex 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex_macros 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -681,7 +680,6 @@ dependencies = [
  "geom 0.1.0 (git+https://github.com/servo/rust-geom)",
  "hyper 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "png 0.1.0 (git+https://github.com/servo/rust-png)",
- "profile 0.0.1",
  "stb_image 0.1.0 (git+https://github.com/servo/rust-stb-image)",
  "url 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "util 0.0.1",
@@ -787,14 +785,22 @@ name = "profile"
 version = "0.0.1"
 dependencies = [
  "libc 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "profile_traits 0.0.1",
  "regex 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "task_info 0.0.1",
  "time 0.1.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "url 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "util 0.0.1",
 ]
 
 [[package]]
+name = "profile_traits"
+version = "0.0.1"
+dependencies = [
+ "time 0.1.19 (registry+https://github.com/rust-lang/crates.io-index)",
+ "url 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "rand"
 version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -840,7 +846,7 @@ dependencies = [
  "net_traits 0.0.1",
  "plugins 0.0.1",
  "png 0.1.0 (git+https://github.com/servo/rust-png)",
- "profile 0.0.1",
+ "profile_traits 0.0.1",
  "rustc-serialize 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "script_traits 0.0.1",
  "selectors 0.1.0 (git+https://github.com/servo/rust-selectors)",
@@ -896,6 +902,7 @@ dependencies = [
  "net_traits 0.0.1",
  "png 0.1.0 (git+https://github.com/servo/rust-png)",
  "profile 0.0.1",
+ "profile_traits 0.0.1",
  "script 0.0.1",
  "time 0.1.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/tests/unit/net/Cargo.toml b/tests/unit/net/Cargo.toml
index 390d6f8ba01..5c265bfec6b 100644
--- a/tests/unit/net/Cargo.toml
+++ b/tests/unit/net/Cargo.toml
@@ -14,9 +14,6 @@ path = "../../../components/net"
 [dependencies.net_traits]
 path = "../../../components/net_traits"
 
-[dependencies.profile]
-path = "../../../components/profile"
-
 [dependencies.util]
 path = "../../../components/util"
 
diff --git a/tests/unit/net/lib.rs b/tests/unit/net/lib.rs
index f44c6fd54cd..959133da74f 100644
--- a/tests/unit/net/lib.rs
+++ b/tests/unit/net/lib.rs
@@ -6,7 +6,6 @@
 
 extern crate net;
 extern crate net_traits;
-extern crate profile;
 extern crate url;
 extern crate util;