https://bugs.webkit.org/show_bug.cgi?id=88555

Reviewed by Eric Carlson.

Source/WebCore:

Test: media/media-controller-time-constant.html

To keep MediaController.currentTime stable, add a new m_position variable and
a new m_clearPositionTimer timer.  Both must be mutable variables as they will
be updated from within const functions.  Calls to currentTime() will result in
stable values until the next runloop iteration.

* html/MediaController.cpp:
(MediaController::MediaController):
(MediaController::currentTime):
(MediaController::setCurrentTime):
(MediaController::clearPositionTimerFired):
* html/MediaController.h:

LayoutTests:

* media/media-controller-time-constant-expected.txt: Added.
* media/media-controller-time-constant.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@123386 268f45cc-cd09-0410-ab3c-d52691b4dbfc