Latching in iframes is not working as expected
https://bugs.webkit.org/show_bug.cgi?id=136729
<rdar://problem/18370549>

Reviewed by Simon Fraser.

Source/WebCore:

Test: platform/mac/fast/scrolling/scrolling-iframe-100pct.html

Correct latching behavior by moving the concept of latching from the event handler to the main frame.
The event handlers are per-document, and can improperly latch to the iframe element (rather than the
scrollable content of the iframe) resulting in incorrect behavior.

Also move the wheel event delta tracking to the main frame, as this is similarly "top-level" in nature.

* WebCore.vcxproj/WebCore.vcxproj: Add new LatchedState class.
* WebCore.vcxproj/WebCore.vcxproj.filters: Ditto.
* WebCore.xcodeproj/project.pbxproj: Ditto.
* page/EventHandler.cpp:
(WebCore::EventHandler::EventHandler): Update constructor after moving some members to the new
LatchedState object.
(WebCore::EventHandler::clear): Call 'clear' on the LatchedState class.
(WebCore::EventHandler::platformRecordWheelEvent):  Update for new LatchedState class.
(WebCore::EventHandler::handleWheelEvent): Ditto.
(WebCore::EventHandler::clearLatchedState): Ditto.
(WebCore::EventHandler::defaultWheelEventHandler): Ditto.
* page/EventHandler.h:
* page/LatchedState.cpp: Added.
(WebCore::LatchedState::LatchedState):
(WebCore::LatchedState::~LatchedState):
(WebCore::LatchedState::clear):
(WebCore::LatchedState::setWheelEventElement):
(WebCore::LatchedState::setWidgetIsLatched):
(WebCore::LatchedState::setPreviousWheelScrolledElement):
(WebCore::LatchedState::setScrollableContainer):
* page/LatchedState.h: Added.
(WebCore::LatchedState::wheelEventElement):
(WebCore::LatchedState::frame):
(WebCore::LatchedState::setFrame):
(WebCore::LatchedState::widgetIsLatched):
(WebCore::LatchedState::previousWheelScrolledElement):
(WebCore::LatchedState::scrollableContainer):
(WebCore::LatchedState::startedGestureAtScrollLimit):
(WebCore::LatchedState::setStartedGestureAtScrollLimit):
* page/MainFrame.cpp:
(WebCore::MainFrame::MainFrame): Update for new members (LatchedState and WheelEventDeltaTracker)
* page/MainFrame.h:
* page/mac/EventHandlerMac.mm:
(WebCore::EventHandler::platformPrepareForWheelEvents): Use mainFrame-located latching information.
(WebCore::EventHandler::platformRecordWheelEvent): Use mainFrame-located wheel event delta tracking.
(WebCore::EventHandler::platformCompleteWheelEvent): Make sure to use the latched frame as well as
the latched element so that events get routed properly.
(WebCore::EventHandler::platformCompletePlatformWidgetWheelEvent): Update for new mainFrame
location for latched state information.

LayoutTests:

* platform/mac/fast/scrolling/scroll-iframe-webkit1-latching-bug-expected.txt: Added.
* platform/mac/fast/scrolling/scroll-iframe-webkit1-latching-bug.html: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@173784 268f45cc-cd09-0410-ab3c-d52691b4dbfc
[CoordinatedGraphics][EFL] window.scrollTo(x, y) doesn't work when fixed layout is enabled
https://bugs.webkit.org/show_bug.cgi?id=136917

Reviewed by Darin Adler.

Source/WebCore:

When fixed layout is enabled, scrollTo doesn't work on EFL port with coordinated graphics.
Since updateScrollbars() doesn't update scroll position when delegatesScrolling() is enabled.
To fix this issue, EFL port should update scroll position based on WK2 port. This patch
update scroll position in FrameView::requestScrollPositionUpdate() as Mac port.

TestWebKitAPI: Tools/TestWebKitAPI/Tests/WebKit2/efl/WKViewScrollTo

* page/FrameView.cpp:
(WebCore::FrameView::requestScrollPositionUpdate):

Tools:

Added WKViewScrollTo.cpp and scrollTo.html to test this issue.

* TestWebKitAPI/PlatformEfl.cmake:
* TestWebKitAPI/Tests/WebKit2/efl/WKViewScrollTo.cpp: Added.
(TestWebKitAPI::didFinishLoadForFrame):
(TestWebKitAPI::TEST):
* TestWebKitAPI/Tests/WebKit2/efl/scrollTo.html: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@173785 268f45cc-cd09-0410-ab3c-d52691b4dbfc