Port BatteryMonitor into Device Service

services/device/device_service.h

Index: services/device/device_service.h
diff --git a/services/device/device_service.h b/services/device/device_service.h
index e08b6320e60e920a3d7172d42ccd1b5f059b61ec..63a090fde27a4901f40b0f5cda67e18ba6f57c91 100644
--- a/services/device/device_service.h
+++ b/services/device/device_service.h
@@ -6,12 +6,18 @@
 #define SERVICES_DEVICE_DEVICE_SERVICE_H_
 
 #include "base/memory/ref_counted.h"
+#include "device/battery/battery_monitor.mojom.h"
 #include "device/power_monitor/public/interfaces/power_monitor.mojom.h"
 #include "device/time_zone_monitor/public/interfaces/time_zone_monitor.mojom.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "services/service_manager/public/cpp/interface_factory.h"
+#include "services/service_manager/public/cpp/interface_provider.h"
 #include "services/service_manager/public/cpp/service.h"
 
+#if defined(OS_ANDROID)
+#include "base/android/scoped_java_ref.h"
+#endif
+
 namespace device {
 
 class TimeZoneMonitor;
@@ -21,6 +27,10 @@ std::unique_ptr<service_manager::Service> CreateDeviceService(
 
 class DeviceService
     : public service_manager::Service,
+#if !defined(OS_ANDROID)
+      // On Android the Device Service provides BatteryMonitor via Java.
+      public service_manager::InterfaceFactory<BatteryMonitor>,
+#endif
       public service_manager::InterfaceFactory<mojom::PowerMonitor>,
       public service_manager::InterfaceFactory<mojom::TimeZoneMonitor> {
  public:
@@ -33,6 +43,12 @@ class DeviceService
   bool OnConnect(const service_manager::ServiceInfo& remote_info,
                  service_manager::InterfaceRegistry* registry) override;
 
+#if !defined(OS_ANDROID)
+  // InterfaceFactory<BatteryMonitor>:
+  void Create(const service_manager::Identity& remote_identity,
+              BatteryMonitorRequest request) override;
+#endif
+
   // InterfaceFactory<mojom::PowerMonitor>:
   void Create(const service_manager::Identity& remote_identity,
               mojom::PowerMonitorRequest request) override;
@@ -41,6 +57,19 @@ class DeviceService
   void Create(const service_manager::Identity& remote_identity,
               mojom::TimeZoneMonitorRequest request) override;
 
+#if defined(OS_ANDROID)
+  // Binds |java_interface_provider_| to an interface registry that exposes
+  // factories for the interfaces that are provided via Java on Android.
+  void InitializeJavaInterfaceProviderIfNeeded();
+
+  // InterfaceProvider that is bound to the Java-side interface registry.
+  service_manager::InterfaceProvider java_interface_provider_;
+
+  // To manage the lifetime of the registry that is bound to
+  // |java_interface_provider_|, this class keeps a reference to it.
+  base::android::ScopedJavaGlobalRef<jobject> java_interface_registry_;

[blundell, 2017/01/24 11:35:43]

AFAICT, there is nothing holding a reference to the created InterfaceRegistry on
the Java side, which is why I'm doing it here. However, my Java-fu is weak, and
I don't know if there is magic going on under the covers in the Java bindings
code.

[Sam McNally, 2017/01/25 05:53:06]

The bindings code will manage its lifetime.

The C++ side of WatcherImpl keeps a reference to it while it's watching it. That
chains Connector -> RouterImpl -> generated bindings (I think) -> mojo interface
impl.

[blundell, 2017/01/25 15:00:34]

Awesome, thanks! Done.

+#endif
+
   std::unique_ptr<device::TimeZoneMonitor> time_zone_monitor_;
 
   scoped_refptr<base::SingleThreadTaskRunner> file_task_runner_;