Auto merge of #11580 - szeged:allowedservices, r=jdm

Allowed services support

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---
<!-- 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
- [ ] These changes fix #__ (github issue number if applicable).

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- [ ] There are tests for these changes OR
- [X] These changes do not require tests because there are no webbluetooth test api implementation yet.

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components/net_traits/bluetooth_scanfilter.rs

@@ -2,6 +2,7 @@
  * 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::collections::HashSet;
 use std::slice::Iter;
 
 // A device name can never be longer than 29 bytes. An adv packet is at most
@@ -16,6 +17,14 @@ impl ServiceUUIDSequence {
     pub fn new(vec: Vec<String>) -> ServiceUUIDSequence {
         ServiceUUIDSequence(vec)
     }
+
+    fn get_services_set(&self) -> HashSet<String> {
+        let mut set = HashSet::new();
+        for s in self.0.iter() {
+            set.insert(s.clone());
+        }
+        set
+    }
 }
 
 #[derive(Deserialize, Serialize)]
@@ -69,6 +78,14 @@ impl BluetoothScanfilterSequence {
     pub fn iter(&self) -> Iter<BluetoothScanfilter> {
         self.0.iter()
     }
+
+    fn get_services_set(&self) -> HashSet<String> {
+        let mut set = HashSet::new();
+        for filter in self.iter() {
+            set = &set | &filter.services.get_services_set();
+        }
+        set
+    }
 }
 
 #[derive(Deserialize, Serialize)]
@@ -90,4 +107,8 @@ impl RequestDeviceoptions {
     pub fn get_filters(&self) -> &BluetoothScanfilterSequence {
         &self.filters
     }
+
+    pub fn get_services_set(&self) -> HashSet<String> {
+        &self.filters.get_services_set() | &self.optional_services.get_services_set()
+    }
 }