https://bugs.webkit.org/show_bug.cgi?id=99491

Reviewed by Dean Jackson.

In preparation for using tile cache layers in place of CATiledLayer,
add a new PlatformCALayer layer type LayerTypePageTileCacheLayer,
since the page tile cache will have some different behavior from
other tile cache layers.

Generalize code that was looking at LayerTypeTileCacheLayer to use
usesTileCacheLayer() if it applies to both types of tile caches.

* platform/graphics/ca/GraphicsLayerCA.cpp:
(WebCore::GraphicsLayerCA::GraphicsLayerCA):
(WebCore::GraphicsLayerCA::recursiveCommitChanges): Show the tile
wash for tiled layers as well as layers with transforms (the tile
wash is just for debugging).
(WebCore::GraphicsLayerCA::platformCALayerDidCreateTiles):
(WebCore::GraphicsLayerCA::swapFromOrToTiledLayer):
* platform/graphics/ca/PlatformCALayer.h:
(WebCore::PlatformCALayer::usesTileCacheLayer):
(PlatformCALayer):
* platform/graphics/ca/mac/PlatformCALayerMac.mm:
(PlatformCALayer::PlatformCALayer):
(PlatformCALayer::~PlatformCALayer):
(PlatformCALayer::tiledBacking):
* platform/graphics/mac/WebLayer.mm:
(drawLayerContents): Avoid double-drawing the repaint counter in tile cache layers.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@131489 268f45cc-cd09-0410-ab3c-d52691b4dbfc