[chromium] Update VideoLayerChromium textures after texture resources are reclaimed

[chromium] Update VideoLayerChromium textures after texture resources are reclaimed
https://bugs.webkit.org/show_bug.cgi?id=68742

Reviewed by James Robinson.

Source/WebCore:

If video textures are reclaimed (such as during a visibility change on
a tab), the dirty rect for the layer is empty and it skips out of
updating compositor resources, leaving the video textures invalid.
Instead, check the textures here to make sure they're still valid
first before early out so that they can get reupdated if necessary.

Additionally, fix a small bug in pushPropertiesTo where 1 plane RGB
videos would not get drawn because all 3 planes didn't have valid
textures.

Test: compositing/video-page-visibility.html

* platform/graphics/chromium/VideoLayerChromium.cpp:
(WebCore::VideoLayerChromium::VideoLayerChromium):
(WebCore::VideoLayerChromium::cleanupResources):
(WebCore::VideoLayerChromium::updateCompositorResources):
(WebCore::VideoLayerChromium::pushPropertiesTo):
(WebCore::VideoLayerChromium::setLayerTreeHost):
(WebCore::VideoLayerChromium::texturesValid):
* platform/graphics/chromium/VideoLayerChromium.h:

LayoutTests:

Without this patch, this video texture is invalid.

* compositing/video-page-visibility-expected.png: Added.
* compositing/video-page-visibility-expected.txt: Added.
* compositing/video-page-visibility.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@95957 268f45cc-cd09-0410-ab3c-d52691b4dbfc