Add DOMWindowLifecycleObserver/Notifier and make DeviceMotionController a DOMWindowLifecycleObserver so we can remove the direct dependency on DeviceMotionController in DOMWindow::removeAllEventListeners()


BUG=

Review URL: https://chromiumcodereview.appspot.com/22272008

git-svn-id: svn://svn.chromium.org/blink/trunk@155956 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Make HAVE(ISDEBUGGERPRESENT) a local macro (instead of a global macro) as it is only used in wtf/Assertions.cpp.

BUG=

Review URL: https://chromiumcodereview.appspot.com/22472006

git-svn-id: svn://svn.chromium.org/blink/trunk@155957 bbb929c8-8fbe-4397-9dbb-9b2b20218538