Add support for MediaTrackConstraints

[Manishearth]

This uses the WebIDL attributes-on-types support landed in #22958 to fill out the MediaTrackConstraints dictionary for constraints that servo-media supports.

r? @jdm

---

This change is 

[highfive]

Heads up! This PR modifies the following files:

• @asajeffrey: components/script/dom/bindings/codegen/CodegenRust.py, components/script/dom/webidls/MediaDevices.webidl, components/script/dom/rtcpeerconnection.rs, components/script/dom/bindings/trace.rs, components/script/dom/bindings/codegen/parser/WebIDL.py and 2 more
• @KiChjang: components/script/dom/bindings/codegen/CodegenRust.py, components/script/dom/webidls/MediaDevices.webidl, components/script/dom/rtcpeerconnection.rs, components/script/dom/bindings/trace.rs, components/script/dom/bindings/codegen/parser/WebIDL.py and 2 more

[highfive]

Warning

• These commits modify script code, but no tests are modified. Please consider adding a test!

[bors-servo]

☔ The latest upstream changes (presumably #22872) made this pull request unmergeable. Please resolve the merge conflicts.

[CYBAI]

Errors about fmt in Travis:

info: downloading component 'rustfmt'
info: installing component 'rustfmt'
Diff in /home/travis/build/servo/servo/components/script/dom/mediadevices.rs at line 2:
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
+use crate::dom::bindings::codegen::Bindings::MediaDevicesBinding::MediaStreamConstraints;
+use crate::dom::bindings::codegen::Bindings::MediaDevicesBinding::{self, MediaDevicesMethods};
 use crate::dom::bindings::codegen::UnionTypes::BooleanOrMediaTrackConstraints;
 use crate::dom::bindings::codegen::UnionTypes::ClampedUnsignedLongOrConstrainULongRange as ConstrainULong;
 use crate::dom::bindings::codegen::UnionTypes::DoubleOrConstrainDoubleRange as ConstrainDouble;
Diff in /home/travis/build/servo/servo/components/script/dom/mediadevices.rs at line 8:
-use crate::dom::bindings::codegen::Bindings::MediaDevicesBinding::MediaStreamConstraints;
-use crate::dom::bindings::codegen::Bindings::MediaDevicesBinding::{self, MediaDevicesMethods};
 use crate::dom::bindings::reflector::reflect_dom_object;
 use crate::dom::bindings::reflector::DomObject;
 use crate::dom::bindings::root::DomRoot;
Diff in /home/travis/build/servo/servo/components/script/dom/mediadevices.rs at line 15:
 use crate::dom::mediastream::MediaStream;
 use crate::dom::promise::Promise;
 use dom_struct::dom_struct;
-use servo_media::ServoMedia;
 use servo_media::streams::capture::{Constrain, ConstrainRange, MediaTrackConstraintSet};
+use servo_media::ServoMedia;
 use std::rc::Rc;
 
 #[dom_struct]
Diff in /home/travis/build/servo/servo/components/script/dom/mediadevices.rs at line 74:
                 frame_rate: convert_cdouble(&c.parent.frameRate),
                 sample_rate: convert_culong(&c.parent.sampleRate),
             })
-        }
+        },
     }
 }
 
Diff in /home/travis/build/servo/servo/components/script/dom/mediadevices.rs at line 94:
                 // the unspecified case is treated as all three being none
                 None
             }
-        }
+        },
     }
 }
 
Diff in /home/travis/build/servo/servo/components/script/dom/mediadevices.rs at line 114:
                 // the unspecified case is treated as all three being none
                 None
             }
-        }
+        },
     }
 }
 
Run `./mach fmt` to fix the formatting

[Manishearth]

Patches being upstreamed in https://bugzilla.mozilla.org/show_bug.cgi?id=1359269#c4

We can wait for that to land, or just land this as is and re-sync webidl later.

[Manishearth]

This is now ready for review again, r? @jdm

[jdm]

@bors-servo r+

[bors-servo]

📌 Commit ce635b7 has been approved by jdm

[bors-servo]

⌛ Testing commit ce635b7 with merge 12c60cb...

[bors-servo]

💔 Test failed - mac-rel-wpt2

[jdm]

@bors-servo retry

[bors-servo]

⌛ Testing commit ce635b7 with merge db313cf...

[bors-servo]

💔 Test failed - linux-rel-wpt

[Manishearth]

@bors-servo retry

• crash: Failed to receive a response from live font cache (thread LayoutThread PipelineId { namespace_id: PipelineNamespaceId(1), index: PipelineIndex(1) }, at components/gfx/font_cache_thread.rs:522)

(will file intermittent later)

[bors-servo]

⌛ Testing commit ce635b7 with merge d6eef04...

[jdm]

That's #21067.

[bors-servo]

💔 Test failed - linux-rel-css

[jdm]

@bors-servo retry

[bors-servo]

⌛ Testing commit ce635b7 with merge 0f3108c...

[bors-servo]

☀️ Test successful - android-mac, arm32, arm64, linux-rel-css, linux-rel-wpt, mac-rel-css1, mac-rel-css2, mac-rel-wpt1, mac-rel-wpt2, mac-rel-wpt3, mac-rel-wpt4, magicleap, status-taskcluster
Approved by: jdm
Pushing 0f3108c to master...