Benchmark to measure SkSurface copy on write performance

Benchmark to measure SkSurface copy on write performance
Committed: https://code.google.com/p/skia/source/detail?r=8718

[Justin Novosad, 2013-04-16 20:33:30]

PTAL

[reed1, 2013-04-16 20:37:24]

https://codereview.chromium.org/14297008/diff/1/bench/DeferredSurfaceCopyBenc...
File bench/DeferredSurfaceCopyBench.cpp (right):

https://codereview.chromium.org/14297008/diff/1/bench/DeferredSurfaceCopyBenc...
bench/DeferredSurfaceCopyBench.cpp:39: info.fWidth = referenceDevice->width();
Is it important to match this size? Seems like the results will be more
repeatable if we just hard-code a given size.

https://codereview.chromium.org/14297008/diff/1/bench/DeferredSurfaceCopyBenc...
bench/DeferredSurfaceCopyBench.cpp:58: SkImage* image =
drawingCanvas.newImageSnapshot();
I think you can collaps these two lines down to just

SkAutoTUnref<SkImage> image(drawingCanvas.newImageSnapshot());

https://codereview.chromium.org/14297008/diff/1/bench/DeferredSurfaceCopyBenc...
bench/DeferredSurfaceCopyBench.cpp:66: drawingCanvas.drawPaint(paint);
this is a non-trival call, in terms of time, if the canvas is large. If you are
just trying to trigger a change at all, why not drawRect(1x1 rect)?

[Justin Novosad, 2013-04-16 20:50:48]

New Patch

https://codereview.chromium.org/14297008/diff/1/bench/DeferredSurfaceCopyBenc...
File bench/DeferredSurfaceCopyBench.cpp (right):

https://codereview.chromium.org/14297008/diff/1/bench/DeferredSurfaceCopyBenc...
bench/DeferredSurfaceCopyBench.cpp:39: info.fWidth = referenceDevice->width();
On 2013/04/16 20:37:24, reed1 wrote:
> Is it important to match this size? Seems like the results will be more
> repeatable if we just hard-code a given size.

Done.

https://codereview.chromium.org/14297008/diff/1/bench/DeferredSurfaceCopyBenc...
bench/DeferredSurfaceCopyBench.cpp:58: SkImage* image =
drawingCanvas.newImageSnapshot();
On 2013/04/16 20:37:24, reed1 wrote:
> I think you can collaps these two lines down to just
> 
> SkAutoTUnref<SkImage> image(drawingCanvas.newImageSnapshot());

Done.

https://codereview.chromium.org/14297008/diff/1/bench/DeferredSurfaceCopyBenc...
bench/DeferredSurfaceCopyBench.cpp:66: drawingCanvas.drawPaint(paint);
On 2013/04/16 20:37:24, reed1 wrote:
> this is a non-trival call, in terms of time, if the canvas is large. If you
are
> just trying to trigger a change at all, why not drawRect(1x1 rect)?
To make contents recognized as discardable I need the draw op to cover the
entire canvas. So just did a large rect.

[reed1, 2013-04-16 21:09:45]

lgtm