Issue 5751 - Removing legacy gecko support

lib/hooks.js

-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-function hook(obj, name, func, cleanup)
-{
-  let orig = obj[name];
-  let origDesc = Object.getOwnPropertyDescriptor(obj, name);
-  let dumbOverrideAttempt = false;
-
-  let newFunc = function()
-  {
-    let params = arguments;
-    try
-    {
-      let result = func.apply(this, params);
-      if (typeof result == "object")
-        params = result;
-    }
-    catch(e)
-    {
-      Cu.reportError(e);
-    }
-
-    try
-    {
-      return orig.apply(this, params);
-    }
-    finally
-    {
-      if (typeof cleanup == "function")
-        cleanup();
-    }
-  };
-  newFunc.toString = function()
-  {
-    dumbOverrideAttempt = true;
-    return orig.toString();
-  };
-  newFunc.toSource = function()
-  {
-    dumbOverrideAttempt = true;
-    return orig.toSource();
-  };
-
-  Object.defineProperty(obj, name, {
-    get: function()
-    {
-      dumbOverrideAttempt = false;
-      return newFunc;
-    },
-    set: function(value)
-    {
-      if (dumbOverrideAttempt)
-      {
-        orig = value;
-      }
-      else
-      {
-        delete obj[name];
-        obj[name] = value;
-      }
-    },
-    enumerable: true,
-    configurable: true
-  });
-
-  return function()
-  {
-    Object.defineProperty(obj, name, origDesc);
-  };
-}
-exports.hook = hook;