Provides the functionality intercepting the page request (HTTP or XHR).
It depends on installation of Page Extensions and provides following methods:
- getRequestTypeDone() - obtains the last request intercepted by code in Page Extensions
- clearRequestTypeDone() - clears the last request (sets the NONE) and returns the last request type set
- waitForRequestTypeChange() - waits until the request done will change to value other than NONE