Fix displacement transition bug for horizontal case

Task-number: QTBUG-29944

Upstream-Status: Backport https://codereview.qt-project.org/49226
Signed-off-by: Florian Haenel <florian.haenel@lge.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

Change-Id: I23381f7a1d2c8d3c6df007b5b11c12b0db3bb1e9
Fix wrong calculation of viewPort for transitions

Viewport is calculated wrong for horizontal layout in a second instance

Task-number: QTBUG-29944
Task-Number: QTBUG-31546

Upstream-Status: Pending

Looks like backport of https://codereview.qt-project.org/49226 but this
one was applied in previous patch, this change looks the same but is
in different part of qquickitemview.cpp and ISN'T applied yet in dev
branch.

Signed-off-by: Florian Haenel <florian.haenel@lge.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

Change-Id: I136ae4484278d14f796613505e3f38c65ec51ebe
Fix null-pointer access in QQuickVisualDataModelPrivate

I observed null cachItem->contextData which lead to null-pointer access
on cacheItem->contextData->destroy().

Task-number: QTBUG-31439

Upstream-Status: Backport https://codereview.qt-project.org/57789

Signed-of-by: Florian Haenel <florian.haenel@lge.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

Change-Id: I91f28a3ee1ac83446ecde1801a1cb7962fb883f3
Avoid swizzling on OpenGL ES when possible

Add support for APPLE_texture_format_BGRA8888,
IMG_texture_format_BGRA8888,
EXT_texture_format_BGRA8888 and EXT_bgra. The apple one acts
just like the desktop EXT_bgra one, so they need slightly
different handling than the ES extensions.

This change also has the benefit that we no longer have a dedicated
ES path.

Upstream-Status: Backport https://codereview.qt-project.org/46549
Signed-off-by: Florian Haenel <florian.haenel@lge.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

Change-Id: I5ecb0a02c3a7bd984d6752fa87163726118b93de