Auto merge of #12136 - ConnorGBrewster:servo_version_reporter, r=asajeffrey

Send servo version in mozbrowser error.

<!-- Please describe your changes on the following line: -->
Adds support for sending a version string to b.html so we can put the servo version in the auto generated issue reports.

r? @asajeffrey

---
<!-- 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 #12083 (github issue number if applicable).

<!-- Either: -->
- [ ] There are tests for these changes OR
- [X] These changes do not require tests because sending servo version on mozbrwosererror for issue reporter.

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components/script/dom/htmliframeelement.rs

@@ -49,6 +49,7 @@ use style::attr::{AttrValue, LengthOrPercentageOrAuto};
 use style::context::ReflowGoal;
 use url::Url;
 use util::prefs::mozbrowser_enabled;
+use util::servo_version;
 
 bitflags! {
     #[derive(JSTraceable, HeapSizeOf)]
@@ -360,6 +361,7 @@ impl MozBrowserEventDetailBuilder for HTMLIFrameElement {
                     type_: Some(DOMString::from(error_type.name())),
                     description: description.map(DOMString::from),
                     report: report.map(DOMString::from),
+                    version: Some(DOMString::from_string(servo_version().into())),
                 }.to_jsval(cx, rval);
             },
             MozBrowserEvent::SecurityChange(https_state) => {