Remove docked windows entirely in M59.

chrome/common/extensions/api/windows.json

Index: chrome/common/extensions/api/windows.json
diff --git a/chrome/common/extensions/api/windows.json b/chrome/common/extensions/api/windows.json
index ed3f6013c7e49821b6a936c8f22ddffa46ec508f..17eb6fd896ae57299796cf2542f38149dccbdf53 100644
--- a/chrome/common/extensions/api/windows.json
+++ b/chrome/common/extensions/api/windows.json
@@ -20,7 +20,22 @@
         "id": "WindowState",
         "type": "string",
         "description": "The state of this browser window. Under some circumstances a Window may not be assigned state property, for example when querying closed windows from the $(ref:sessions) API.",
-        "enum": ["normal", "minimized", "maximized", "fullscreen", "docked"]
+        "enum": [{
+          "name": "normal",
+          "description": "Normal window state (i.e. not minimized, maximized, or fullscreen)."
+        }, {
+          "name": "minimized",
+          "description": "Minimized window state."
+        }, {
+          "name": "maximized",
+          "description": "Maximized window state."
+        }, {
+          "name": "fullscreen",
+          "description": "Fullscreen window state."
+        }, {
+          "name": "docked",
+          "description": "<i>Deprecated since Chrome M59.</i> Docked windows are no longer supported. This state will be converted to \"normal\"."
+        }]
       },
       {
         "id": "Window",