https://bugs.webkit.org/show_bug.cgi?id=126533

Reviewed by Tim Horton.

These classes currently maintain a set of separate fields to represent the view state;
combine these into a single field, and allow WebPage to send the combined update rather
than individual changes.

Maintain existing interface for WebKit1 clients.

Source/WebCore: 

* WebCore.exp.in:
    - Added WebCore::setViewState, removed WebCore::setIsVisuallyIdle.
* page/FocusController.cpp:
(WebCore::FocusController::FocusController):
    - Initialize combined m_viewState.
(WebCore::FocusController::setFocused):
    - Calls setViewState.
(WebCore::FocusController::setFocusedInternal):
    - setFocused -> setFocusedInternal.
(WebCore::FocusController::setViewState):
    - Added, update all ViewState flags.
(WebCore::FocusController::setActive):
    - Calls setViewState.
(WebCore::FocusController::setActiveInternal):
    - setActive -> setActiveInternal.
(WebCore::FocusController::setContentIsVisible):
    - Calls setViewState.
(WebCore::FocusController::setContentIsVisibleInternal):
    - setContentIsVisible -> setContentIsVisibleInternal.
* page/FocusController.h:
(WebCore::FocusController::isActive):
(WebCore::FocusController::isFocused):
(WebCore::FocusController::contentIsVisible):
    - Implemented in terms of ViewState.
* page/Page.cpp:
(WebCore::Page::Page):
    - Initialize using PageInitialViewState.
(WebCore::Page::setIsInWindow):
    - Calls setViewState.
(WebCore::Page::setIsInWindowInternal):
    - setIsInWindow -> setIsInWindowInternal.
(WebCore::Page::setIsVisuallyIdleInternal):
    - setIsVisuallyIdle -> setIsVisuallyIdleInternal.
(WebCore::Page::setViewState):
    - Added, update all ViewState flags, including FocusController.
(WebCore::Page::setIsVisible):
    - Calls setViewState.
(WebCore::Page::setIsVisibleInternal):
    - setIsVisible -> setIsVisibleInternal.
(WebCore::Page::visibilityState):
    - m_isVisible -> isVisible()
(WebCore::Page::hiddenPageCSSAnimationSuspensionStateChanged):
    - m_isVisible -> isVisible()
* page/Page.h:
(WebCore::Page::isVisible):
(WebCore::Page::isInWindow):
    - Implemented in terms of ViewState.
(WebCore::Page::scriptedAnimationsSuspended):
    - Combined member fields into ViewState::Flags.

Source/WebKit/mac: 

* WebView/WebView.mm:
(-[WebView _windowWillOrderOnScreen:]):
(-[WebView _windowWillOrderOffScreen:]):
    - remove calls to FocusController::setContentIsVisible, these are redundant
      (this is handled when page visibility is set).

Source/WebKit2: 

* WebProcess/WebPage/WebPage.cpp:
(WebKit::WebPage::WebPage):
    - Combined separate calls to Page::setViewState.
(WebKit::WebPage::updateIsInWindow):
    - Simplied from setIsInWindow.
(WebKit::WebPage::setViewState):
    - Combined separate calls to Page::setViewState.
* WebProcess/WebPage/WebPage.h:
    - Declare updateIsInWindow.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@162452 268f45cc-cd09-0410-ab3c-d52691b4dbfc