Add Pause and Resume to Web TTS & Extension TTS APIs

chrome/common/extensions/api/tts_engine.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.
 
 [
   {
     "namespace": "ttsEngine",
     "functions": [
       {
         "name": "sendTtsEvent",
@@ skipping 78 matching lines @@
                 "$ref": "tts.TtsEvent",
                 "description": "The event from the text-to-speech engine indicating the status of this utterance."
               }
             ]
           }
         ]
       },
       {
         "name": "onStop",
         "type": "function",
-        "description": "Fired when a call is made to tts.stop and this extension may be in the middle of speaking. If an extension receives a call to onStop and speech is already stopped, it should do nothing (not raise an error)."
+        "description": "Fired when a call is made to tts.stop and this extension may be in the middle of speaking. If an extension receives a call to onStop and speech is already stopped, it should do nothing (not raise an error). If speech is in the paused state, this should cancel the paused state."
+      },
+      {
+        "name": "onPause",
+        "type": "function",
+        "description": "Optional: if an engine supports the pause event, it should pause the current utterance being spoken, if any, until it receives a resume event or stop event. Note that a stop event should also clear the paused state."
+      },
+      {
+        "name": "onResume",
+        "type": "function",
+        "description": "Optional: if an engine supports the pause event, it should also support the resume event, to continue speaking the current utterance, if any. Note that a stop event should also clear the paused state."
       }
     ]
   }
 ]