IndexedDB: clean up scheduleTask return type
https://bugs.webkit.org/show_bug.cgi?id=108361

Reviewed by Tony Chang.

This is just a code simplification now that the
synchronous consumers of scheduleTask are gone.

No new tests: pure refactor.

* Modules/indexeddb/IDBDatabaseBackendImpl.cpp:
(WebCore::IDBDatabaseBackendImpl::setIndexesReady):
(WebCore::IDBDatabaseBackendImpl::runIntVersionChangeTransaction):
* Modules/indexeddb/IDBTransactionBackendImpl.cpp:
(WebCore::IDBTransactionBackendImpl::scheduleTask):
* Modules/indexeddb/IDBTransactionBackendImpl.h:
(WebCore::IDBTransactionBackendImpl::scheduleTask):
(IDBTransactionBackendImpl):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141332 268f45cc-cd09-0410-ab3c-d52691b4dbfc
[mac] ImageBuffer should create accelerated buffers for small canvases, but we shouldn't force them to create compositing layers
https://bugs.webkit.org/show_bug.cgi?id=107804
<rdar://problem/11752381>

Reviewed by Simon Fraser.

Make all canvases IOSurface-backed if requested, instead of having a size threshold
under which we won't use accelerated canvas.

Make requiresCompositingForCanvas take the size of the canvas into account, using
the threshold which was previously in ImageBuffer to determine whether or not a
canvas should be forced into a compositing layer.

This improves canvas performance on some benchmarks
(http://www.mikechambers.com/html5/javascript/QuadTree/examples/collision.html, for example)
significantly, in cases where canvases which fall below the size limit
(and thus are unaccelerated) are being drawn rapidly into either accelerated
tiles or another accelerated canvas, by preventing excessive copying to/from the GPU.

* platform/graphics/cg/ImageBufferCG.cpp:
(WebCore):
(WebCore::ImageBuffer::ImageBuffer):
* rendering/RenderLayerCompositor.cpp:
(WebCore::RenderLayerCompositor::requiresCompositingForCanvas):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141333 268f45cc-cd09-0410-ab3c-d52691b4dbfc