RefCounter<T>::Event -> RefCounterEvent

RefCounter<T>::Event -> RefCounterEvent
https://bugs.webkit.org/show_bug.cgi?id=154767

Reviewed by Darin Adler.

RefCounter<T>::Event is kinda verbose to use, and there is no need for this
to be specific to a particular typeof RefCounter. Move the enum class up to
the top level & rename to RefCounterEvent.

Source/WebCore:

* page/PageThrottler.cpp:
(WebCore::PageThrottler::PageThrottler):
(WebCore::m_audiblePluginHysteresis):
(WebCore::m_mediaActivityCounter):
(WebCore::m_pageLoadActivityCounter):
* platform/VNodeTracker.cpp:
(WebCore::VNodeTracker::singleton):
(WebCore::VNodeTracker::VNodeTracker):
(WebCore::m_lastWarningTime):

Source/WebKit2:

Also remove UserObservablePageToken - this is vestigial & not really offering
anything over just using UserObservablePageCounter::Token directly.

* UIProcess/Plugins/PluginProcessManager.cpp:
(WebKit::PluginProcessManager::PluginProcessManager):
* UIProcess/Plugins/PluginProcessManager.h:
* UIProcess/Plugins/mac/PluginProcessManagerMac.mm:
(WebKit::PluginProcessManager::updateProcessSuppressionDisabled):
* UIProcess/ProcessThrottler.cpp:
(WebKit::ProcessThrottler::ProcessThrottler):
(WebKit::m_backgroundCounter):
(WebKit::m_suspendMessageCount):
* UIProcess/ProcessThrottler.h:
* UIProcess/WebPageProxy.h:
* UIProcess/WebProcessPool.cpp:
(WebKit::WebProcessPool::WebProcessPool):
(WebKit::m_processSuppressionDisabledForPageCounter):
(WebKit::m_hiddenPageThrottlingAutoIncreasesCounter):
* UIProcess/WebProcessPool.h:

Source/WTF:

* wtf/RefCounter.h:
(WTF::RefCounter<T>::Count::ref):
(WTF::RefCounter<T>::Count::deref):

Tools:

* TestWebKitAPI/Tests/WTF/RefCounter.cpp:
(TestWebKitAPI::TEST):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@197360 268f45cc-cd09-0410-ab3c-d52691b4dbfc