[Texmap] Code cleanup: remove unused boundingRect/visibleRect calculations

[Texmap] Code cleanup: remove unused boundingRect/visibleRect calculations
https://bugs.webkit.org/show_bug.cgi?id=68897

Reviewed by Andreas Kling.

No new functionality so no new tests.

* platform/graphics/texmap/TextureMapperNode.cpp:
(WebCore::TextureMapperNode::computeAllTransforms):
(WebCore::TextureMapperNode::computeTiles):
(WebCore::TextureMapperNode::syncCompositingState):
* platform/graphics/texmap/TextureMapperNode.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@96120 268f45cc-cd09-0410-ab3c-d52691b4dbfc