Update FakeSensorProvider to use a ReceiverSet instead of a Receiver.

This makes the Fake usable in more circumstances and is in line
with the real implementation.

Bug: 1024716
Change-Id: I7ca40f3df08f4575255c0008e9db010888e1788e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1928108Reviewed-by: Colin Blundell <blundell@chromium.org>
Reviewed-by: Tim Volodine <timvolodine@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Fergal Daly <fergal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#719095}

services/device/public/cpp/test/fake_sensor_and_provider.cc

@@ -188,8 +188,7 @@ void FakeSensorProvider::GetSensor(mojom::SensorType type,
 
 void FakeSensorProvider::Bind(
     mojo::PendingReceiver<mojom::SensorProvider> receiver) {
-  DCHECK(!receiver_.is_bound());
-  receiver_.Bind(std::move(receiver));
+  receivers_.Add(this, std::move(receiver));
 }
 
 void FakeSensorProvider::SetAmbientLightSensorData(double value) {

services/device/public/cpp/test/fake_sensor_and_provider.h

@@ -7,7 +7,7 @@
 
 #include "base/macros.h"
 #include "mojo/public/cpp/bindings/pending_receiver.h"
-#include "mojo/public/cpp/bindings/receiver.h"
+#include "mojo/public/cpp/bindings/receiver_set.h"
 #include "mojo/public/cpp/bindings/remote.h"
 #include "mojo/public/cpp/system/buffer.h"
 #include "services/device/public/cpp/generic_sensor/sensor_reading.h"
@@ -141,7 +141,7 @@ class FakeSensorProvider : public mojom::SensorProvider {
   bool gyroscope_is_available_ = true;
   bool relative_orientation_sensor_is_available_ = true;
   bool absolute_orientation_sensor_is_available_ = true;
-  mojo::Receiver<mojom::SensorProvider> receiver_{this};
+  mojo::ReceiverSet<mojom::SensorProvider> receivers_{};
   mojo::ScopedSharedBufferHandle shared_buffer_handle_;
   mojo::ScopedSharedBufferMapping shared_buffer_mapping_;