extensions: tabs: set tab id to -1 for app/devtools windows

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 1a41ba11ad9e02f838020301327ad394934d1aeb..c5300aa484c5e4e93c1df4d50ac37fad365e1fb7 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, "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."},
+          "id": {"type": "integer", "minimum": -1, "description": "The ID of the tab. Tab IDs are unique within a browser session. Under some circumstances a Tab may not be -1, for example when querying foreign tabs using the $(ref:sessions) API, in which case a session ID may be present, or for applications and devtools windows."},

[dgozman, 2015/07/16 12:05:50]

"may not be -1" -> "may be -1"

[llandwerlin-old, 2015/07/16 12:09:23]

Done, thanks.

           // 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."},