Add a service to track devices selected by the user.

chrome/browser/devtools/device/usb/android_usb_browsertest.cc

Index: chrome/browser/devtools/device/usb/android_usb_browsertest.cc
diff --git a/chrome/browser/devtools/device/usb/android_usb_browsertest.cc b/chrome/browser/devtools/device/usb/android_usb_browsertest.cc
index 585254680e45d0664f320e6afe14924a1080f05b..249b999269a66095e031824bb5303ced87f762fa 100644
--- a/chrome/browser/devtools/device/usb/android_usb_browsertest.cc
+++ b/chrome/browser/devtools/device/usb/android_usb_browsertest.cc
@@ -162,22 +162,22 @@ class MockUsbDeviceHandle : public UsbDeviceHandle {
   }
 
   // Async IO. Can be called on any thread.
-  virtual void ControlTransfer(const UsbEndpointDirection direction,
-                               const TransferRequestType request_type,
-                               const TransferRecipient recipient,
-                               const uint8 request,
-                               const uint16 value,
-                               const uint16 index,
+  virtual void ControlTransfer(UsbEndpointDirection direction,
+                               TransferRequestType request_type,
+                               TransferRecipient recipient,
+                               uint8 request,
+                               uint16 value,
+                               uint16 index,
                                net::IOBuffer* buffer,
-                               const size_t length,
-                               const unsigned int timeout,
+                               size_t length,
+                               unsigned int timeout,
                                const UsbTransferCallback& callback) OVERRIDE {}
 
-  virtual void BulkTransfer(const UsbEndpointDirection direction,
-                            const uint8 endpoint,
+  virtual void BulkTransfer(UsbEndpointDirection direction,
+                            uint8 endpoint,
                             net::IOBuffer* buffer,
-                            const size_t length,
-                            const unsigned int timeout,
+                            size_t length,
+                            unsigned int timeout,
                             const UsbTransferCallback& callback) OVERRIDE {
     if (direction == device::USB_DIRECTION_OUTBOUND) {
       if (remaining_body_length_ == 0) {
@@ -304,22 +304,22 @@ class MockUsbDeviceHandle : public UsbDeviceHandle {
                    query.size));
   }
 
-  virtual void InterruptTransfer(const UsbEndpointDirection direction,
-                                 const uint8 endpoint,
+  virtual void InterruptTransfer(UsbEndpointDirection direction,
+                                 uint8 endpoint,
                                  net::IOBuffer* buffer,
-                                 const size_t length,
-                                 const unsigned int timeout,
+                                 size_t length,
+                                 unsigned int timeout,
                                  const UsbTransferCallback& callback) OVERRIDE {
   }
 
   virtual void IsochronousTransfer(
-      const UsbEndpointDirection direction,
-      const uint8 endpoint,
+      UsbEndpointDirection direction,
+      uint8 endpoint,
       net::IOBuffer* buffer,
-      const size_t length,
-      const unsigned int packets,
-      const unsigned int packet_length,
-      const unsigned int timeout,
+      size_t length,
+      unsigned int packets,
+      unsigned int packet_length,
+      unsigned int timeout,
       const UsbTransferCallback& callback) OVERRIDE {}
 
  protected: