Add UMA to hotword trigger extension.

chrome/common/extensions/api/_permission_features.json

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This features file defines permissions for extension APIs implemented
 // under src/chrome.
 // See extensions/common/features/* to understand this file, in particular
 // feature.h, simple_feature.h, and base_feature_provider.h.
 
 // To add a new whitelisted ID, SHA-1 it and force it to uppercase. In Bash:
@@ skipping 701 matching lines @@
       "D5736E4B5CF695CB93A2FB57E4FDC6E5AFAB6FE2",  // http://crbug.com/312900.
       "D57DE394F36DC1C3220E7604C575D29C51A6C495",  // http://crbug.com/319444.
       "3F65507A3B39259B38C8173C6FFA3D12DF64CCE9",  // http://crbug.com/371562.
       "06BE211D5F014BAB34BC22D9DDA09C63A81D828E",  // Official XKB virtual kbd
       "CFBF7EE448FA48960FFDA7CEB30F7A21B26AA981",  // Official m17n virtual kbd
       "B9EF10DDFEA11EF77873CC5009809E5037FC4C7A",  // Google input tools
       "7D7A4B147FE39908A5AF13F85E38989C54BBE41C",  // http://crbug.com/374955
       "0EEDFC0EED87871237213F34EBC7B4982A195C95",  // http://crbug.com/374955
       "D2DAA9362153E8A5E3CF593E6DF4666421ABAD21",  // http://crbug.com/374965
       "D7986543275120831B39EF28D1327552FC343960",  // http://crbug.com/378067
-      "A291B26E088FA6BA53FFD72F0916F06EBA7C585A"   // http://crbug.com/378067
+      "A291B26E088FA6BA53FFD72F0916F06EBA7C585A",  // http://crbug.com/378067
+      "62CCAAD339E6451BBF97C4BBDF758E934A05AD0B"   // Hotword triggering
     ]
   },
   "mdns": {
     "channel": "stable",
     "extension_types": ["extension", "platform_app"],
     "whitelist": [
       "63ED55E43214C211F82122ED56407FF1A807F2A3",  // Dev
       "FA01E0B81978950F2BC5A50512FD769725F57510",  // Beta
       "B11A93E7E5B541F8010245EBDE2C74647D6C14B9",  // Canary
       "F155646B5D1CA545F7E1E4E20D573DFDD44C2540",  // Google Cast Beta
@@ skipping 317 matching lines @@
   "webstorePrivate": {
     "channel": "stable",
     "extension_types": ["extension", "legacy_packaged_app", "hosted_app"],
     "whitelist": [
       "B44D08FD98F1523ED5837D78D0A606EA9D6206E5",  // Web Store
       "2653F6F6C39BC6EEBD36A09AFB92A19782FF7EB4",  // Enterprise Web Store
       "2779FA8B45841D61A37207CCFAC9CB393964FE5B"   // Login Proxy (prototype)
     ]
   }
 }