Sessions API - previously Session Restore API. Supports restoring currently open foreign windows an…

chrome/common/extensions/api/tabs.json

Index: chrome/common/extensions/api/tabs.json
diff --git a/chrome/common/extensions/api/tabs.json b/chrome/common/extensions/api/tabs.json
index def80145a795b166fded9416d00d659223ab106a..4b4077d65605728a6c26253da835ef622b839723 100644
--- a/chrome/common/extensions/api/tabs.json
+++ b/chrome/common/extensions/api/tabs.json
@@ -11,7 +11,7 @@
         "id": "Tab",
         "type": "object",
         "properties": {
-          "id": {"type": "integer", "minimum": 0, "description": "The ID of the tab. Tab IDs are unique within a browser session."},
+          "id": {"type": "integer", "minimum": 0, "optional": true, "description": "The ID of the tab. Tab IDs are unique within a browser session. Under some circumstances a Tab may not be assigned an ID, for example when querying foreign tabs using the $ref:sessions API, in which case a session ID may be present."},
           // TODO(kalman): Investigate how this is ending up as -1 (based on window type? a bug?) and whether it should be optional instead.
           "index": {"type": "integer", "minimum": -1, "description": "The zero-based index of the tab within its window."},
           "windowId": {"type": "integer", "minimum": 0, "description": "The ID of the window the tab is contained within."},
@@ -26,7 +26,8 @@
           "status": {"type": "string", "optional": true, "description": "Either <em>loading</em> or <em>complete</em>."},
           "incognito": {"type": "boolean", "description": "Whether the tab is in an incognito window."},
           "width": {"type": "integer", "optional": true, "description": "The width of the tab in pixels."},
-          "height": {"type": "integer", "optional": true, "description": "The height of the tab in pixels."}
+          "height": {"type": "integer", "optional": true, "description": "The height of the tab in pixels."},
+          "sessionId": {"type": "string", "optional": true, "description": "The session ID used to uniquely identify a Tab obtained from the $ref:sessions API."}
         }
       },
       {