Handle RESCAN events from the Bluetooth chooser by starting or extending a discovery session.

I also added interfaces to support tests that this works, documented in https://github.com/WebBluetoothCG/web-bluetooth/pull/165.

BUG=533185
TBR=mkwst@chromium.org

Review URL: https://codereview.chromium.org/1353053002

Cr-Commit-Position: refs/heads/master@{#350586}

2 files changed, 18 insertions, 0 deletions

diff --git a/device/bluetooth/test/mock_bluetooth_adapter.cc b/device/bluetooth/test/mock_bluetooth_adapter.cc
index 8054d69..26ae68b 100644
--- a/device/bluetooth/test/mock_bluetooth_adapter.cc
+++ b/device/bluetooth/test/mock_bluetooth_adapter.cc
@@ -8,10 +8,21 @@
 
 namespace device {
 
+using testing::Invoke;
+using testing::_;
+
 MockBluetoothAdapter::Observer::Observer() {}
 MockBluetoothAdapter::Observer::~Observer() {}
 
 MockBluetoothAdapter::MockBluetoothAdapter() {
+  ON_CALL(*this, AddObserver(_))
+      .WillByDefault(Invoke([this](BluetoothAdapter::Observer* observer) {
+        this->BluetoothAdapter::AddObserver(observer);
+      }));
+  ON_CALL(*this, RemoveObserver(_))
+      .WillByDefault(Invoke([this](BluetoothAdapter::Observer* observer) {
+        this->BluetoothAdapter::RemoveObserver(observer);
+      }));
 }
 
 MockBluetoothAdapter::~MockBluetoothAdapter() {}
diff --git a/device/bluetooth/test/mock_bluetooth_adapter.h b/device/bluetooth/test/mock_bluetooth_adapter.h
index 6d1ee73..775adee 100644
--- a/device/bluetooth/test/mock_bluetooth_adapter.h
+++ b/device/bluetooth/test/mock_bluetooth_adapter.h
@@ -109,6 +109,13 @@ class MockBluetoothAdapter : public BluetoothAdapter {
   BluetoothAdapter::ConstDeviceList GetConstMockDevices();
   BluetoothAdapter::DeviceList GetMockDevices();
 
+  // The observers are maintained by the default behavior of AddObserver() and
+  // RemoveObserver(). Test fakes can use this function to notify the observers
+  // about events.
+  base::ObserverList<device::BluetoothAdapter::Observer>& GetObservers() {
+    return observers_;
+  }
+
  protected:
   void AddDiscoverySession(
       BluetoothDiscoveryFilter* discovery_filter,