Add browser tests for USB device add/remove events.

extensions/test/data/api_test/usb/add_event/manifest.json

Index: extensions/test/data/api_test/usb/add_event/manifest.json
diff --git a/extensions/test/data/api_test/hid/add_event/manifest.json b/extensions/test/data/api_test/usb/add_event/manifest.json
similarity index 70%
copy from extensions/test/data/api_test/hid/add_event/manifest.json
copy to extensions/test/data/api_test/usb/add_event/manifest.json
index 81ed7840c059c30738b888baabf479a00632ef20..d5a7d6f02b6e482bfeb51bf4b630bae2d5bf7170 100644
--- a/extensions/test/data/api_test/hid/add_event/manifest.json
+++ b/extensions/test/data/api_test/usb/add_event/manifest.json
@@ -1,14 +1,14 @@
 {
-  "name": "chrome.hid.onDeviceAdded",
+  "name": "chrome.usb.onDeviceAdded",
   "version": "0.1",
-  "description": "browser test for chrome.hid.onDeviceAdded event",
+  "description": "browser test for chrome.usb.onDeviceAdded event",
   "app": {
     "background": {
       "scripts": ["background.js"]
     }
   },
   "permissions": [
-    "hid",
+    "usb",
     // This is a test device emulated by the mocks enabled for the test.
     { "usbDevices": [{ "vendorId": 6353, "productId": 22768 }]}
   ]