Auto merge of #20132 - nakul02:issue_19223, r=jdm

Profiler for blocked IpcReceiver::recv()

<!-- Please describe your changes on the following line: -->

Implements feature #19223

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #19223 (github issue number if applicable).

<!-- Either: -->
- [x] There are tests for these changes

<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

WIP.
@jdm - this is the new profiler : "Blocked at IPC Receive"
Should I dig through all the calls to `ipc::channel` and replace them with this profiled `IpcReceiver`?

![screenshot from 2018-02-27 01-35-37](https://user-images.githubusercontent.com/5394361/36721061-b46edea4-1b5e-11e8-91d6-7faba742f237.png)

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/20132)
<!-- Reviewable:end -->

1 files changed, 3 insertions, 3 deletions

diff --git a/components/script/dom/vr.rs b/components/script/dom/vr.rs
index fc3bc1c05b3..3283015dd14 100644
--- a/components/script/dom/vr.rs
+++ b/components/script/dom/vr.rs
@@ -19,8 +19,8 @@ use dom::promise::Promise;
 use dom::vrdisplay::VRDisplay;
 use dom::vrdisplayevent::VRDisplayEvent;
 use dom_struct::dom_struct;
-use ipc_channel::ipc;
 use ipc_channel::ipc::IpcSender;
+use profile_traits::ipc;
 use std::rc::Rc;
 use webvr_traits::{WebVRDisplayData, WebVRDisplayEvent, WebVREvent, WebVRMsg};
 use webvr_traits::{WebVRGamepadData, WebVRGamepadEvent, WebVRGamepadState};
@@ -61,7 +61,7 @@ impl VRMethods for VR {
         let promise = Promise::new(&self.global());
 
         if let Some(webvr_thread) = self.webvr_thread() {
-            let (sender, receiver) = ipc::channel().unwrap();
+            let (sender, receiver) = ipc::channel(self.global().time_profiler_chan().clone()).unwrap();
             webvr_thread.send(WebVRMsg::GetDisplays(sender)).unwrap();
             match receiver.recv().unwrap() {
                 Ok(displays) => {
@@ -234,7 +234,7 @@ impl VR {
     // motion capture or drawing applications.
     pub fn get_gamepads(&self) -> Vec<DomRoot<Gamepad>> {
         if let Some(wevbr_sender) = self.webvr_thread() {
-            let (sender, receiver) = ipc::channel().unwrap();
+            let (sender, receiver) = ipc::channel(self.global().time_profiler_chan().clone()).unwrap();
             let synced_ids = self.gamepads.borrow().iter().map(|g| g.gamepad_id()).collect();
             wevbr_sender.send(WebVRMsg::GetGamepads(synced_ids, sender)).unwrap();
             match receiver.recv().unwrap() {