[sensors] Add Generic Sensor platform unit tests.

device/generic_sensor/mock_platform_sensor_provider.cc

Index: device/generic_sensor/mock_platform_sensor_provider.cc
diff --git a/device/generic_sensor/mock_platform_sensor_provider.cc b/device/generic_sensor/mock_platform_sensor_provider.cc
new file mode 100644
index 0000000000000000000000000000000000000000..494e1130e59f0ac94cce6818639d6134214c6893
--- /dev/null
+++ b/device/generic_sensor/mock_platform_sensor_provider.cc
@@ -0,0 +1,30 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/memory/singleton.h"
+
+#include "device/generic_sensor/mock_platform_sensor.h"
+#include "device/generic_sensor/mock_platform_sensor_provider.h"
+
+namespace device {
+
+// static
+MockPlatformSensorProvider* MockPlatformSensorProvider::GetInstance() {
+  return base::Singleton<
+      MockPlatformSensorProvider,
+      base::LeakySingletonTraits<MockPlatformSensorProvider>>::get();
+}
+
+MockPlatformSensorProvider::MockPlatformSensorProvider() = default;
+
+MockPlatformSensorProvider::~MockPlatformSensorProvider() = default;
+
+scoped_refptr<PlatformSensor> MockPlatformSensorProvider::CreateSensorInternal(
+    mojom::SensorType type,
+    mojo::ScopedSharedBufferMapping mapping,
+    uint64_t buffer_size) {
+  return new MockPlatformSensor(type, std::move(mapping), buffer_size, this);
+}
+
+}  // namespace device