Fix race between orientation sensor fallback and listener removal

This change fixes a DCHECK which can fire due to the internal state of
the DeviceOrientationEventPump becoming invalid when a page removes its
event listener before the failure to initialize the relative orientation
sensor is received.

This should've been handled by the existing code in DidStartIfPossible()
however since DeviceSensorEntry::HandleSensorError() updates the sensor
state to kNotInitialized the information that the event listener was
removed and so the sensor should move into the kSuspended state after
initialization was lost, resulting in the fallback sensor instead
entering the kActive state. DidStartIfPossible() now checks the pump
state, which will be set to kStopped, instead of the DeviceSensorEntry
state.

New unit tests have been added to exercise some of these "stopped while
initializing" cases more carefully.

Bug: 1409077
Change-Id: I3e7b6adf12dbb04e012486cef86d8b70a7f9378d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4190679
Auto-Submit: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Matt Reynolds <mattreynolds@chromium.org>
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1096396}

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

@@ -104,6 +104,10 @@ void FakeSensorProvider::GetSensor(mojom::SensorType type,
     return;
   }
 
+  if (sensor_requested_callback_) {
+    std::move(sensor_requested_callback_).Run(type);
+  }
+
   SensorReadingSharedBuffer* buffer = GetSensorReadingSharedBufferForType(type);
 
   std::unique_ptr<FakeSensor> sensor;

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

@@ -70,6 +70,13 @@ class FakeSensorProvider : public mojom::SensorProvider {
   void Bind(mojo::PendingReceiver<mojom::SensorProvider> receiver);
   bool is_bound() const;
 
+  // Configures a callback which is invoked when GetSensor() is called, allowing
+  // tests to take an action before the response callback is invoked.
+  void set_sensor_requested_callback(
+      base::OnceCallback<void(mojom::SensorType)> callback) {
+    sensor_requested_callback_ = std::move(callback);
+  }
+
   void set_ambient_light_sensor_is_available(
       bool ambient_light_sensor_is_available) {
     ambient_light_sensor_is_available_ = ambient_light_sensor_is_available;
@@ -149,6 +156,7 @@ class FakeSensorProvider : public mojom::SensorProvider {
   SensorReading gyroscope_reading_;
   SensorReading relative_orientation_sensor_reading_;
   SensorReading absolute_orientation_sensor_reading_;
+  base::OnceCallback<void(mojom::SensorType)> sensor_requested_callback_;
   bool ambient_light_sensor_is_available_ = true;
   bool accelerometer_is_available_ = true;
   bool linear_acceleration_sensor_is_available_ = true;

third_party/blink/renderer/modules/device_orientation/device_orientation_event_pump.cc

@@ -144,8 +144,7 @@ void DeviceOrientationEventPump::DidStartIfPossible() {
     // then fall back to using absolute_orientation_sensor_.
     attempted_to_fall_back_to_absolute_orientation_sensor_ = true;
     absolute_orientation_sensor_->Start(sensor_provider_.get());
-    if (relative_orientation_sensor_->state() ==
-        DeviceSensorEntry::State::kShouldSuspend) {
+    if (state() == PumpState::kStopped) {
       // If SendStopMessage() was called before the OnSensorCreated() callback
       // registered that relative_orientation_sensor_ was not able to connect
       // then absolute_orientation_sensor_ needs to be Stop()'d so that it

third_party/blink/renderer/modules/device_orientation/device_orientation_event_pump.h

@@ -6,6 +6,8 @@
 #define THIRD_PARTY_BLINK_RENDERER_MODULES_DEVICE_ORIENTATION_DEVICE_ORIENTATION_EVENT_PUMP_H_
 
 #include "third_party/blink/renderer/modules/device_orientation/device_sensor_event_pump.h"
+
+#include "third_party/blink/renderer/modules/device_orientation/device_sensor_entry.h"
 #include "third_party/blink/renderer/modules/modules_export.h"
 #include "third_party/blink/renderer/platform/heap/garbage_collected.h"
 
@@ -43,6 +45,14 @@ class MODULES_EXPORT DeviceOrientationEventPump
   void SendStartMessage(LocalFrame& frame) override;
   void SendStopMessage() override;
 
+  DeviceSensorEntry::State GetRelativeSensorStateForTesting() {
+    return relative_orientation_sensor_->state();
+  }
+
+  DeviceSensorEntry::State GetAbsoluteSensorStateForTesting() {
+    return absolute_orientation_sensor_->state();
+  }
+
  protected:
   // DeviceSensorEventPump:
   void FireEvent(TimerBase*) override;