[iOS][WK2] Fix some state reset on crash on the WKWebView
https://bugs.webkit.org/show_bug.cgi?id=133039

Reviewed by Sam Weinig.

This is in no way complete, but this should reduce the undefined states on crash.

* UIProcess/API/Cocoa/WKWebView.mm:
(-[WKWebView _processDidExit]):
If the view is animating, nuke the resize animation. That should be invisible to the user
because the background color is reset to white below.

Reset the contentView frame and scrollview state.

Reset the runtime states. We do not strictly need to reset _needsResetViewStateAfterCommitLoadForMainFrame,
_delayUpdateVisibleContentRects and _hadDelayedUpdateVisibleContentRects but it seems better to have
a clean slate.

(-[WKWebView _beginAnimatedResizeWithUpdates:]):
(-[WKWebView _endAnimatedResize]):
We could have crashes during rotation. To simplify the reset code, the animated resize code
no longer change any state when WKWebView is using a custom content view.

* UIProcess/API/Cocoa/WKWebViewInternal.h:
* UIProcess/ios/PageClientImplIOS.mm:
(WebKit::PageClientImpl::processDidExit):
Send a _processDidExit on the WKWebView too.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@169326 268f45cc-cd09-0410-ab3c-d52691b4dbfc