Remove obsolete Cast extension IDs from various whitelists and files.

extensions/common/api/_api_features.json

Index: extensions/common/api/_api_features.json
diff --git a/extensions/common/api/_api_features.json b/extensions/common/api/_api_features.json
index a1d671c3423437a26bd3a8ab8f8927027d570467..99ac11d3eb4ca36ddbdb49d6e59bdb904861aa3d 100644
--- a/extensions/common/api/_api_features.json
+++ b/extensions/common/api/_api_features.json
@@ -272,11 +272,8 @@
       "896B85CC7E913E11C34892C1425A093C0701D386",  // http://crbug.com/456214
       "11A01C82EF355E674E4F9728A801F5C3CB40D83F",  // http://crbug.com/456214
       "F410C88469990EE7947450311D24B8AF2ADB2595",  // http://crbug.com/456214
-      "226CF815E39A363090A1E547D53063472B8279FA",  // http://crbug.com/574889
-      "C17CD9E6868D7B9C67926E0EC612EA25C768418F",  // http://crbug.com/504940
-      "A45DABDB47A31CC812E5490AB748C7D05E2D32E9",  // http://crbug.com/504940
-      "BFEE2E3B80BE21A645E63E9346DFC383E7CB3BDA",  // http://crbug.com/504940
-      "63ED55E43214C211F82122ED56407FF1A807F2A3",  // http://crbug.com/504940
+      "63ED55E43214C211F82122ED56407FF1A807F2A3",  // Media Router Dev
+      "226CF815E39A363090A1E547D53063472B8279FA",  // Media Router Stable
       // TODO (ntang) Remove the following 2 hashes by 12/31/2017.
       "B620CF4203315F9F2E046EDED22C7571A935958D",  // http://crbug.com/510270
       "B206D8716769728278D2D300349C6CB7D7DE2EF9",  // http://crbug.com/510270
@@ -295,11 +292,8 @@
     "channel": "stable",
     "extension_types": ["platform_app", "extension"],
     "whitelist": [
-      "226CF815E39A363090A1E547D53063472B8279FA",  // http://crbug.com/574889
-      "C17CD9E6868D7B9C67926E0EC612EA25C768418F",  // http://crbug.com/448569
-      "A45DABDB47A31CC812E5490AB748C7D05E2D32E9",
-      "BFEE2E3B80BE21A645E63E9346DFC383E7CB3BDA",
-      "63ED55E43214C211F82122ED56407FF1A807F2A3"
+      "63ED55E43214C211F82122ED56407FF1A807F2A3",   // Media Router Dev
+      "226CF815E39A363090A1E547D53063472B8279FA"    // Media Router Stable
     ]
   },
   "networking.config": {