Do not store flags in qmake.cache with WEBENGINE_CONFIG.
Use directly qtConfig values insted. This makes configuration
more consistent, simplifies handling and avoids passing
values from qtConfig to WEBENIGNE_CONFIG, which then
were passed to gn.

[ChangeLog] Removing WEBENGINE_CONFIG from qtwebengine configure

Change-Id: I1a773fb4bff6d67ad75c237d044998051d92ab51
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

[ChangeLog][Examples] Removed WebEngine Demo Browser example, which got
superseded by the improved WebEngine Widgets Simple Browser.

Task-number: QTBUG-59819
Change-Id: I214e6f5f3a946ed617a9f4d628d3259a69874ca1
Reviewed-by: Kai Koehne <kai.koehne@qt.io>
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

Adds example command line tool 'html2pdf' that loads a URL into
QWebEnginePage and prints it to a pdf file.

Task-number: QTBUG-59823
Change-Id: I898e9a9ecdf819f417876f964d40e494f6095c99
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Michael Brüning <michael.bruning@qt.io>

Demonstrates how to inject and remove stylesheets using the
user scripts API.

Change-Id: If498365897618f873fa96d7a7b04a370e196618e
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

Task-number: QTBUG-59822
Change-Id: Iee69f10fefa223313ca112f096b65446b4156ac1
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

Adds an example ('videoplayer') showing how to enable the Fullscreen
API[1] in QWebEngineView. This is one of the missing examples blocking
the removal of demobrowser.

[1]: https://fullscreen.spec.whatwg.org



Task-number: QTBUG-59820
Change-Id: Ib02a1556515d87e595ca54c2bce18c9144030fbc
Reviewed-by: Kai Koehne <kai.koehne@qt.io>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Michal Klocek <michal.klocek@qt.io>

Instead of adding individual example projects into SUBDIRS from the
top-level examples.pro, add a .pro file for both /examples/webengine
and /examples/webenginewidgets that handles them.

This way, it's easier to e.g. build all webengine examples from
binary packages, as the top-level examples.pro is not packaged.

Task-number: QTBUG-57124
Change-Id: I8cf8ac7b13b86306b31bc43c79e3d8272193b1d3
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>