Move string descriptor getters from UsbDeviceHandle to UsbDevice.

device/usb/usb_device_impl.h

Index: device/usb/usb_device_impl.h
diff --git a/device/usb/usb_device_impl.h b/device/usb/usb_device_impl.h
index e95c8dbc9add72a27033e2a7da9300b4a82d493b..f0d22b251071cd940ee541b97859cc47228ba1ee 100644
--- a/device/usb/usb_device_impl.h
+++ b/device/usb/usb_device_impl.h
@@ -39,6 +39,9 @@ class UsbDeviceImpl : public UsbDevice {
   virtual scoped_refptr<UsbDeviceHandle> Open() OVERRIDE;
   virtual bool Close(scoped_refptr<UsbDeviceHandle> handle) OVERRIDE;
   virtual const UsbConfigDescriptor& GetConfiguration() OVERRIDE;
+  virtual bool GetManufacturer(base::string16* manufacturer) OVERRIDE;
+  virtual bool GetProduct(base::string16* product) OVERRIDE;
+  virtual bool GetSerialNumber(base::string16* serial_number) OVERRIDE;
 
  protected:
   friend class UsbServiceImpl;
@@ -60,6 +63,15 @@ class UsbDeviceImpl : public UsbDevice {
   base::ThreadChecker thread_checker_;
   PlatformUsbDevice platform_device_;
 
+#if defined(OS_LINUX)
+  // On Linux these properties are read from sysfs when the device is enumerated
+  // to avoid hitting the permission broker on Chrome OS for a real string
+  // descriptor request.
+  std::string manufacturer_;
+  std::string product_;
+  std::string serial_number_;
+#endif
+
   // The active configuration descriptor is not read immediately but cached for
   // later use.
   bool current_configuration_cached_;