[Chromium] Move popup location detection code from WebViewImpl to WebPagePopupImpl

[Chromium] Move popup location detection code from WebViewImpl to WebPagePopupImpl
https://bugs.webkit.org/show_bug.cgi?id=84116

Reviewed by Kentaro Hara.

This makes no behavior change. Just move some code.
To fix Bug 84007, WebPagePopupImpl needs to know if the popup is
above the target element or below the target element.

* src/WebPagePopupImpl.cpp:
(WebKit::WebPagePopupImpl::init): Move some code from WebViewImpl::openPagePopup().
* src/WebPagePopupImpl.h:
(WebPagePopupImpl): Rename an argument name.
* src/WebViewImpl.cpp:
(WebKit::WebViewImpl::openPagePopup): Move some code to WebPagePopupImpl::init().

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@114336 268f45cc-cd09-0410-ab3c-d52691b4dbfc