Port device_generic_sensor to be hosted in Device Service.

services/device/device_service.cc

Index: services/device/device_service.cc
diff --git a/services/device/device_service.cc b/services/device/device_service.cc
index a0aae54d745cd30b2806cbdb39077f33085415c2..6510d98bbab952c5ef8736f837929a59a93cf2db 100644
--- a/services/device/device_service.cc
+++ b/services/device/device_service.cc
@@ -14,6 +14,7 @@
 #include "device/battery/battery_monitor.mojom.h"
 #include "device/battery/battery_monitor_impl.h"
 #include "device/battery/battery_status_service.h"
+#include "device/generic_sensor/sensor_provider_impl.h"
 #include "device/sensors/device_sensor_host.h"
 #include "device/wake_lock/wake_lock_context_provider.h"
 #include "mojo/public/cpp/system/message_pipe.h"
@@ -94,6 +95,7 @@ bool DeviceService::OnConnect(const service_manager::ServiceInfo& remote_info,
   registry->AddInterface<mojom::OrientationAbsoluteSensor>(this);
   registry->AddInterface<mojom::PowerMonitor>(this);
   registry->AddInterface<mojom::ScreenOrientationListener>(this);
+  registry->AddInterface<mojom::SensorProvider>(this);

[blundell, 2017/03/27 14:56:52]

We should preserve the check about the feature being enabled, right?

[ke.he, 2017/03/28 05:41:11]

The check code is: "if (base::FeatureList::IsEnabled(features::kGenericSensor))"
The features::kGenericSensor is defined in
//content/public/common/content_features.cc.

I feel we cannot add deps from //service to //content/public/, right? But I find
there is already existed deps from //service to //content/public.(in
service/navigation).

If above deps is allowed, just need to add the
"if (base::FeatureList::IsEnabled(features::kGenericSensor))" here.
Else, my plan is to create a new file services_device_features.cc in
//service/device/public/cpp, and move the definition of features::kGenericSensor
into it. Any comments? thanks!

[blundell, 2017/03/28 07:03:52]

Ah, great point! You are correct that a dep from //services/foo to //content is
in general no good (//services/navigation is essentially a sketch of what a
navigation service could look like). Your plan to do the move sounds perfect.

   registry->AddInterface<mojom::TimeZoneMonitor>(this);
   registry->AddInterface<mojom::WakeLockContextProvider>(this);
 
@@ -215,6 +217,15 @@ void DeviceService::Create(const service_manager::Identity& remote_identity,
 }
 
 void DeviceService::Create(const service_manager::Identity& remote_identity,
+                           mojom::SensorProviderRequest request) {
+  if (io_task_runner_) {
+    io_task_runner_->PostTask(
+        FROM_HERE, base::Bind(&device::SensorProviderImpl::Create,
+                              file_task_runner_, base::Passed(&request)));
+  }
+}
+
+void DeviceService::Create(const service_manager::Identity& remote_identity,
                            mojom::TimeZoneMonitorRequest request) {
   if (!time_zone_monitor_)
     time_zone_monitor_ = TimeZoneMonitor::Create(file_task_runner_);