Log Message:
webkit-gtk: update to 2.20.1.

WebKitGTK+ 2.20.1 released!

    Improve error message when Gigacage cannot allocate virtual memory.
    Add missing WebKitWebProcessEnumTypes.h to webkit-web-extension.h.
    Improve web process memory monitor thresholds.
    Fix a web process crash when the web view is created and destroyed quickly.
    Fix a network process crash when load is cancelled while searching for \ 
stored HTTP auth credentials.
    Fix the build when ENABLE_VIDEO, ENABLE_WEB_AUDIO and ENABLE_XSLT are disabled.
    Fix several crashes and rendering issues.
    Translation updates: Brazilian Portuguese, Czech.

WebKitGTK+ 2.20.0 released!

    New API to retrieve and delete cookies with WebKitCookieManager.
    New web process API to detect when form is submitted via JavaScript.
    Several improvements and fixes in the touch/gestures support.
    Support for the “system” CSS font family.
    Complex text rendering improvements and fixes.
    Added a low power mode.
    More complete and spec compliant WebDriver implementation.