bluetooth: Implement known_service_uuids for Peripherals.

third_party/WebKit/LayoutTests/resources/bluetooth/web-bluetooth-test.js

Index: third_party/WebKit/LayoutTests/resources/bluetooth/web-bluetooth-test.js
diff --git a/third_party/WebKit/LayoutTests/resources/bluetooth/web-bluetooth-test.js b/third_party/WebKit/LayoutTests/resources/bluetooth/web-bluetooth-test.js
index 4ff126f700c4495d0dc470b3101db2cc936a94bf..ad490b037c60f60f028b9ba1241d6e0315b6ec18 100644
--- a/third_party/WebKit/LayoutTests/resources/bluetooth/web-bluetooth-test.js
+++ b/third_party/WebKit/LayoutTests/resources/bluetooth/web-bluetooth-test.js
@@ -26,9 +26,26 @@
     return mojo_;
   }
 
+  async function toMojoCentralState(state) {
+    let mojo = await loadFakeBluetoothInterfaces();
+
+    let mojo_central_state;
+    switch (state) {
+      case 'absent':
+        return  mojo.CentralState.ABSENT;
+      case 'powered-off':
+        return mojo.CentralState.POWERED_OFF;
+      case 'powered-on':
+        return mojo.CentralState.POWERED_ON;
+      default:
+        throw `Unsupported value ${state} for state.`;
+    }
+  }
+
   class FakeBluetooth {
     constructor() {
       this.fake_bluetooth_ptr_ = undefined;
+      this.fake_central_ = undefined;
     }
 
     // Set it to indicate whether the platform supports BLE. For example,
@@ -73,28 +90,16 @@
       await setBluetoothFakeAdapter('');
 
       await this.setLESupported(true);
-      let mojo = await loadFakeBluetoothInterfaces();
-
-      let mojo_manager_state;
-      switch (state) {
-        case 'absent':
-          mojo_manager_state = mojo.CentralState.ABSENT;
-          break;
-        case 'powered-off':
-          mojo_manager_state = mojo.CentralState.POWERED_OFF;
-          break;
-        case 'powered-on':
-          mojo_manager_state = mojo.CentralState.POWERED_ON;
-          break;
-        default:
-          throw `Unsupported value ${state} for state.`;
+      if (this.fake_central_ === undefined) {

[scheib, 2017/05/09 23:33:54]

... continued from previous comment. This logic seems complicated and odd that
we have to handle simulateCentral being called more than once. Perhaps if we
want to update the state of the central later we should just call setState.

Also, code like this seems to be having too many nested awaits. Perhaps we
should have a private method that we can call at top of all FakeBluetooth
methods that ensures mojo is loaded? If code here stayed exactly the same I'd
like to remove the need for getFakeBluetoothInterface and change
toMojoCentralState to be synchronous.

[ortuno, 2017/05/10 06:32:51]

Yeah, I agree. It was a trade-off between convenience e.g. being able to call
setUpPreconnectedDevice and complexity. I guess we can avoid the complexity for
now and introduce it when/if we need it. 
I shuffled the code a bit. I'm slightly worried that toMojoCentralState doesn't
explicitly get the mojo interfaces but then again, why would we use
toMojoCentralState if we haven't initialized mojo_ yet?

+        let {fake_central:fake_central_ptr} =
+          await (await this.getFakeBluetoothInterface_()).simulateCentral(
+            await toMojoCentralState(state));
+        this.fake_central_ = new FakeCentral(fake_central_ptr);
+      } else {
+        await this.fake_central_.setState(state);
       }
 
-      let {fake_central:fake_central_ptr} =
-        await (await this.getFakeBluetoothInterface_()).simulateCentral(
-          mojo_manager_state);
-
-      return new FakeCentral(fake_central_ptr);
+      return this.fake_central_;
     }
 
     async getFakeBluetoothInterface_() {
@@ -120,17 +125,24 @@
       this.peripherals_ = new Map();
     }
 
-    // Simulates a peripheral with |address| and |name| that has already
-    // been connected to the system. If the peripheral existed already it
-    // updates its name.
+    // Simulates a peripheral with |address|, |name| and |known_service_uuids|

[scheib, 2017/05/09 23:33:54]

Describe that array members of known_service_uuids must be of
BluetoothServiceUUID type.

[ortuno, 2017/05/10 06:32:51]

Done.

+    // that has already been connected to the system. If the peripheral existed
+    // already it updates its name and known UUIDs.
     //
     // Platforms offer methods to retrieve devices that have already been
-    // connected to the system or weren't connected through the UA e.g. a
-    // user connected a peripheral through the system's settings. This method is
+    // connected to the system or weren't connected through the UA e.g. a user
+    // connected a peripheral through the system's settings. This method is
     // intended to simulate peripherals that those methods would return.
-    async simulatePreconnectedPeripheral({address, name}) {
+    async simulatePreconnectedPeripheral({
+      address, name, knownServiceUUIDs = []}) {
+
+      // Canonicalize and convert to mojo UUIDs.
+      knownServiceUUIDs.forEach((val, i, arr) => {
+        knownServiceUUIDs[i] = {uuid: BluetoothUUID.getService(val)};
+      });
+
       await this.fake_central_ptr_.simulatePreconnectedPeripheral(
-        address, name);
+        address, name, knownServiceUUIDs);
 
       let peripheral = this.peripherals_.get(address);
       if (peripheral === undefined) {
@@ -140,6 +152,10 @@
 
       return peripheral;
     }
+
+    async setState(state) {
+      await this.fake_central_ptr_.setState(await toMojoCentralState(state));
+    }
   }
 
   class FakePeripheral {