WebTileLayers should honor the acceleratesDrawing flag

WebTileLayers should honor the acceleratesDrawing flag
https://bugs.webkit.org/show_bug.cgi?id=77242
<rdar://problem/10622128>

Reviewed by Dan Bernstein.

* platform/graphics/ca/mac/TileCache.h:
(WebCore::TileCache::acceleratesDrawing):
Add getter.

* platform/graphics/ca/mac/TileCache.mm:
(WebCore::TileCache::TileCache):
Initialize m_acceleratesDrawing.

(WebCore::TileCache::setAcceleratesDrawing):
Set m_acceleratesDrawing and go through all tile layers and update the flag.

(WebCore::TileCache::createTileLayer):
Call -[CALayer setAcceleratesDrawing:] on the newly created layer.

* platform/graphics/ca/mac/WebTileCacheLayer.mm:
(-[WebTileCacheLayer setAcceleratesDrawing:]):
(-[WebTileCacheLayer acceleratesDrawing]):
Call through to the TileCache object.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@106163 268f45cc-cd09-0410-ab3c-d52691b4dbfc