Add the chrome.bluetoothLowEnergy.setAdvertisingInterval API.

device/bluetooth/dbus/fake_bluetooth_le_advertising_manager_client.cc

Index: device/bluetooth/dbus/fake_bluetooth_le_advertising_manager_client.cc
diff --git a/device/bluetooth/dbus/fake_bluetooth_le_advertising_manager_client.cc b/device/bluetooth/dbus/fake_bluetooth_le_advertising_manager_client.cc
index f6aead74c26629b893c7575f9ff30a106e4fdd85..dd00beb81f44a0a76eb7e614e3122b6ff3244556 100644
--- a/device/bluetooth/dbus/fake_bluetooth_le_advertising_manager_client.cc
+++ b/device/bluetooth/dbus/fake_bluetooth_le_advertising_manager_client.cc
@@ -15,8 +15,13 @@
 
 namespace bluez {
 
-const char FakeBluetoothLEAdvertisingManagerClient::kAdvertisingManagerPath[] =
-    "/fake/hci0";
+namespace {
+
+constexpr char kAdvertisingManagerPath[] = "/fake/hci0";
+constexpr uint16_t kMinIntervalMs = 20;
+constexpr uint16_t kMaxIntervalMs = 10240;
+
+}  // namespace
 
 FakeBluetoothLEAdvertisingManagerClient::
     FakeBluetoothLEAdvertisingManagerClient() {}
@@ -83,6 +88,22 @@ void FakeBluetoothLEAdvertisingManagerClient::UnregisterAdvertisement(
   }
 }
 
+void FakeBluetoothLEAdvertisingManagerClient::SetAdvertisingInterval(
+    const dbus::ObjectPath& object_path,
+    uint16_t min_interval_ms,
+    uint16_t max_interval_ms,
+    const base::Closure& callback,
+    const ErrorCallback& error_callback) {
+  if (min_interval_ms < kMinIntervalMs || max_interval_ms > kMaxIntervalMs ||
+      min_interval_ms > max_interval_ms) {
+    // TODO(rkc): Replace this string with the correct constant from service
+    // constants, once cros_system deps are rolled.
+    error_callback.Run("org.bluez.Error.InvalidInterval", "Invalid interval.");
+    return;
+  }
+  callback.Run();
+}
+
 void FakeBluetoothLEAdvertisingManagerClient::
     RegisterAdvertisementServiceProvider(
         FakeBluetoothLEAdvertisementServiceProvider* service_provider) {