bluetooth: Implement simulatePreconnectedPeripheral.

device/bluetooth/public/interfaces/test/fake_bluetooth.mojom

Index: device/bluetooth/public/interfaces/test/fake_bluetooth.mojom
diff --git a/device/bluetooth/public/interfaces/test/fake_bluetooth.mojom b/device/bluetooth/public/interfaces/test/fake_bluetooth.mojom
index add7ea6dc066f357858f4f7ff2e4eda1450697bd..87adedf2a26fee171c01545ae7a904eb65a313c0 100644
--- a/device/bluetooth/public/interfaces/test/fake_bluetooth.mojom
+++ b/device/bluetooth/public/interfaces/test/fake_bluetooth.mojom
@@ -37,4 +37,13 @@ interface FakeBluetooth {
 // Central. See Bluetooth 4.2 Vol 3 Part C 2.2.2 "Roles when Operation over an
 // LE Physical Transport".
 interface FakeCentral {
+  // Simulates a peripheral with |address| and |name| that has already
+  // been connected to the system.
+  //
+  // Platforms offer methods to retrieve devices that have already been
+  // connected to the system or didn't connected through the UA e.g. a

[scheib, 2017/05/03 20:38:48]

"or weren't connected through the user agent, e.g."

[ortuno, 2017/05/04 04:16:21]

Done.

+  // user connected a peripheral through the system's settings. This method is
+  // intended to simulate peripherals that those methods would return.
+  SimulateSystemConnectedPeripheral(string address, string name)
+      => (string peripheral_id);
 };