Whitelist CrOS Camera app to use fileManagerPrivate api.

CrOS Camera app needs to be whitelisted to use fileManagerPrivate API to show the taken photo/video under Downloads/ and be notified for their changes under Downloads/.

BUG=854551

Change-Id: I0ef7654db7b1ac504e051bf64ef9c30e0cb375a4
Reviewed-on: https://chromium-review.googlesource.com/1109674Reviewed-by: Ben Wells <benwells@chromium.org>
Reviewed-by: Toni Barzic <tbarzic@chromium.org>
Commit-Queue: yuli <yuli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569921}

chrome/common/extensions/api/_permission_features.json

@@ -338,7 +338,10 @@
       "A13373C881097323F4DEF392474BE2E28DA6D4ED",  // Gallery
       "8C726564C6DBE7380BAB388DE6CC7EC93EB44B06",  // Video player
       "5065C83E84321221675D20FBE4DC43C655CC8C6F",  // Files app tests
-      "397F221E63F86BE34C30165613E95B6CC8D22A52"   // http://crbug.com/415846
+      "397F221E63F86BE34C30165613E95B6CC8D22A52",  // http://crbug.com/415846
+      "A3E3DE9E9F16B41D4A2FAD106BD6CA76B94A0C94",  // http://crbug.com/854551
+      "C2ABD68C33A5B485971C9638B80D6A2E9CBA78C4",  // http://crbug.com/854551
+      "B41E7F08E1179CC03CBD1F49E57CF353A40ADE07"   // http://crbug.com/854551
     ]
   },
   "fileSystemProvider": [{