Reland: Build a basic Mojo service framework for device/usb

device/core/device_client.h

Index: device/core/device_client.h
diff --git a/device/core/device_client.h b/device/core/device_client.h
index b4a9934e55b12774b8cb1c7dc5ef0016a2ef7582..00fa17902ab70f58e4ea26467a45085fc227f2f1 100644
--- a/device/core/device_client.h
+++ b/device/core/device_client.h
@@ -6,12 +6,17 @@
 #define DEVICE_CORE_DEVICE_CLIENT_H_
 
 #include "base/macros.h"
+#include "third_party/mojo/src/mojo/public/cpp/bindings/interface_request.h"
 
 namespace device {
 
 class HidService;
 class UsbService;
 
+namespace usb {
+class DeviceManager;
+}
+
 // Interface used by consumers of //device APIs to get pointers to the service
 // singletons appropriate for a given embedding application. For an example see
 // //chrome/browser/chrome_device_client.h.
@@ -21,7 +26,7 @@ class DeviceClient {
   DeviceClient();
 
   // Destruction clears the single instance.
-  ~DeviceClient();
+  virtual ~DeviceClient();
 
   // Returns the single instance of |this|.
   static DeviceClient* Get();
@@ -29,6 +34,11 @@ class DeviceClient {
   // Returns the UsbService instance for this embedder.
   virtual UsbService* GetUsbService();
 
+  // Connects a USB DeviceManager client to a concrete implementation. If
+  // no such implementation is available the request is dropped.
+  virtual void ConnectToUSBDeviceManager(
+      mojo::InterfaceRequest<usb::DeviceManager> request);
+
   // Returns the HidService instance for this embedder.
   virtual HidService* GetHidService();