Implementing TabManager extensions API Discard Function.

chrome/common/extensions/api/tabs.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": "tabs",
     "description": "Use the <code>chrome.tabs</code> API to interact with the browser's tab system. You can use this API to create, modify, and rearrange tabs in the browser.",
     "types": [
       { "id": "MutedInfoReason",
@@ skipping 889 matching lines @@
             "description": "Called with the tab's current zoom settings.",
             "parameters": [
               {
                 "$ref": "ZoomSettings",
                 "name": "zoomSettings",
                 "description": "The tab's current zoom settings."
               }
             ]
           }
         ]
+      },
+      {
+        "name": "discard",
+        "type": "function",
+        "description": "Discards a tab from memory. Discarded tabs are still visible on the tab strip and are reloaded when activated.",
+        "parameters": [
+          {
+            "type": "integer",
+            "name": "tabId",
+            "optional": true,
+            "minimum": 0,
+            "description": "The ID of the tab to be discarded; defaults to the least important tab."
+          },
+          {
+            "type": "function",
+            "name": "callback",
+            "optional": true,
+            "description": "Called after the operation is completed.",
+            "parameters": [
+              {
+                "name": "tab",
+                "$ref": "Tab",
+                "description": "Discarded tab if it was successfully discarded. Undefined otherwise."
+              }
+            ]
+          }
+        ]
       }
     ],
     "events": [
       {
         "name": "onCreated",
         "type": "function",
         "description": "Fired when a tab is created. Note that the tab's URL may not be set at the time this event fired, but you can listen to onUpdated events to be notified when a URL is set.",
         "parameters": [
           {
             "$ref": "Tab",
@@ skipping 264 matching lines @@
             "tabId": {"type": "integer", "minimum": 0},
             "oldZoomFactor": {"type": "number"},
             "newZoomFactor": {"type": "number"},
             "zoomSettings": {"$ref": "ZoomSettings"}
           }
         }]
       }
     ]
   }
 ]