GPU benchmarks should track the frequency of impl-thread vs. main-thread scrolls

Track the frequency of impl-thread scrolling vs. main-thread scrolling by introducing the counters |numImplThreadScrolls| and |numMainThreadScrolls|.  These values will be reported as part of the GPU scrolling benchmarks.

BUG=152249
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=159921

[tdanderson, 2012-09-28 16:05:00]

Depends on https://bugs.webkit.org/show_bug.cgi?id=97919 landing first.

[tdanderson, 2012-09-28 17:50:04]

Hi James, would you mind having a look at this patch (and the related WebKit
patch) when you have a moment?

[enne (OOO), 2012-09-28 18:54:29]

https://codereview.chromium.org/10985082/diff/1/cc/CCLayerTreeHostImpl.cpp
File cc/CCLayerTreeHostImpl.cpp (right):

https://codereview.chromium.org/10985082/diff/1/cc/CCLayerTreeHostImpl.cpp#ne...
cc/CCLayerTreeHostImpl.cpp:1038: m_didImplThreadScroll = false;
This seems a little weird to me.  If a scroll gesture begins and ends before you
call rendering stats, then this value will be false.  Would it make sense to
instead keep track of some count and report it or the delta since the last time
rendering stats was called?

[tdanderson, 2012-10-01 19:38:12]

https://codereview.chromium.org/10985082/diff/1/cc/CCLayerTreeHostImpl.cpp
File cc/CCLayerTreeHostImpl.cpp (right):

https://codereview.chromium.org/10985082/diff/1/cc/CCLayerTreeHostImpl.cpp#ne...
cc/CCLayerTreeHostImpl.cpp:1038: m_didImplThreadScroll = false;
On 2012/09/28 18:54:29, enne wrote:
> This seems a little weird to me.  If a scroll gesture begins and ends before
you
> call rendering stats, then this value will be false.  Would it make sense to
> instead keep track of some count and report it or the delta since the last
time
> rendering stats was called?

Thanks for the feedback. Instead of using a boolean, now I'm tracking the
frequency of each scroll type with two counters.

[enne (OOO), 2012-10-01 22:28:45]

Thanks, that seems way more reasonable to me.  LGTM.

[commit-bot: I haz the power, 2012-10-03 14:35:22]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/tdanderson@chromium.org/10985082/5001

[commit-bot: I haz the power, 2012-10-03 14:35:25]

Failed to apply patch for content/renderer/gpu/gpu_benchmarking_extension.cc:
While running patch -p1 --forward --force;
patching file content/renderer/gpu/gpu_benchmarking_extension.cc
Hunk #1 FAILED at 170.
1 out of 1 hunk FAILED -- saving rejects to file
content/renderer/gpu/gpu_benchmarking_extension.cc.rej

[commit-bot: I haz the power, 2012-10-03 16:02:32]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/tdanderson@chromium.org/10985082/11001

[commit-bot: I haz the power, 2012-10-03 18:00:29]

Change committed as 159921