Move serial out of experimental.

chrome/common/extensions/docs/samples.json

 {
   "api": {
     "chrome.alarms.clear": "alarms.html#method-clear",
     "chrome.alarms.clearAll": "alarms.html#method-clearAll",
     "chrome.alarms.create": "alarms.html#method-create",
     "chrome.alarms.get": "alarms.html#method-get",
     "chrome.alarms.getAll": "alarms.html#method-getAll",
     "chrome.alarms.onAlarm": "alarms.html#event-onAlarm",
     "chrome.app.window.create": "app.window.html#method-create",
     "chrome.app.window.focus": "app.window.html#method-focus",
@@ skipping 158 matching lines @@
     "chrome.experimental.processes.getProcessIdForTab": "experimental.processes.html#method-getProcessIdForTab",
     "chrome.experimental.processes.getProcessInfo": "experimental.processes.html#method-getProcessInfo",
     "chrome.experimental.processes.onCreated": "experimental.processes.html#event-onCreated",
     "chrome.experimental.processes.onExited": "experimental.processes.html#event-onExited",
     "chrome.experimental.processes.onUnresponsive": "experimental.processes.html#event-onUnresponsive",
     "chrome.experimental.processes.onUpdated": "experimental.processes.html#event-onUpdated",
     "chrome.experimental.processes.onUpdatedWithMemory": "experimental.processes.html#event-onUpdatedWithMemory",
     "chrome.experimental.processes.terminate": "experimental.processes.html#method-terminate",
     "chrome.experimental.record.captureURLs": "experimental.record.html#method-captureURLs",
     "chrome.experimental.record.replayURLs": "experimental.record.html#method-replayURLs",
-    "chrome.experimental.serial.close": "experimental.serial.html#method-close",
-    "chrome.experimental.serial.flush": "experimental.serial.html#method-flush",
-    "chrome.experimental.serial.getControlSignals": "experimental.serial.html#method-getControlSignals",
-    "chrome.experimental.serial.getPorts": "experimental.serial.html#method-getPorts",
-    "chrome.experimental.serial.open": "experimental.serial.html#method-open",
-    "chrome.experimental.serial.read": "experimental.serial.html#method-read",
-    "chrome.experimental.serial.setControlSignals": "experimental.serial.html#method-setControlSignals",
-    "chrome.experimental.serial.write": "experimental.serial.html#method-write",
     "chrome.experimental.speechInput.isRecording": "experimental.speechInput.html#method-isRecording",
     "chrome.experimental.speechInput.onError": "experimental.speechInput.html#event-onError",
     "chrome.experimental.speechInput.onResult": "experimental.speechInput.html#event-onResult",
     "chrome.experimental.speechInput.onSoundEnd": "experimental.speechInput.html#event-onSoundEnd",
     "chrome.experimental.speechInput.onSoundStart": "experimental.speechInput.html#event-onSoundStart",
     "chrome.experimental.speechInput.start": "experimental.speechInput.html#method-start",
     "chrome.experimental.speechInput.stop": "experimental.speechInput.html#method-stop",
     "chrome.experimental.usb.bulkTransfer": "experimental.usb.html#method-bulkTransfer",
     "chrome.experimental.usb.closeDevice": "experimental.usb.html#method-closeDevice",
     "chrome.experimental.usb.controlTransfer": "experimental.usb.html#method-controlTransfer",
@@ skipping 100 matching lines @@
     "chrome.runtime.getBackgroundPage": "runtime.html#method-getBackgroundPage",
     "chrome.runtime.getManifest": "runtime.html#method-getManifest",
     "chrome.runtime.getURL": "runtime.html#method-getURL",
     "chrome.runtime.onInstalled": "runtime.html#event-onInstalled",
     "chrome.runtime.onSuspend": "runtime.html#event-onSuspend",
     "chrome.runtime.onSuspendCanceled": "runtime.html#event-onSuspendCanceled",
     "chrome.scriptBadge.getAttention": "scriptBadge.html#method-getAttention",
     "chrome.scriptBadge.getPopup": "scriptBadge.html#method-getPopup",
     "chrome.scriptBadge.onClicked": "scriptBadge.html#event-onClicked",
     "chrome.scriptBadge.setPopup": "scriptBadge.html#method-setPopup",
+    "chrome.serial.close": "serial.html#method-close",
+    "chrome.serial.flush": "serial.html#method-flush",
+    "chrome.serial.getControlSignals": "serial.html#method-getControlSignals",
+    "chrome.serial.getPorts": "serial.html#method-getPorts",
+    "chrome.serial.open": "serial.html#method-open",
+    "chrome.serial.read": "serial.html#method-read",
+    "chrome.serial.setControlSignals": "serial.html#method-setControlSignals",
+    "chrome.serial.write": "serial.html#method-write",
     "chrome.socket.bind": "socket.html#method-bind",
     "chrome.socket.connect": "socket.html#method-connect",
     "chrome.socket.create": "socket.html#method-create",
     "chrome.socket.destroy": "socket.html#method-destroy",
     "chrome.socket.disconnect": "socket.html#method-disconnect",
     "chrome.socket.read": "socket.html#method-read",
     "chrome.socket.recvFrom": "socket.html#method-recvFrom",
     "chrome.socket.sendTo": "socket.html#method-sendTo",
     "chrome.socket.setKeepAlive": "socket.html#method-setKeepAlive",
     "chrome.socket.setNoDelay": "socket.html#method-setNoDelay",
@@ skipping 2496 matching lines @@
         "manifest.json",
         "popup.html",
         "popup.js",
         "sample.css"
       ],
       "source_hash": "8e51dc3a9577065d22ce92f3c838edc5ceaf4e65",
       "zip_path": "examples/api/extension/isAllowedAccess.zip"
     }
   ]
 }