Add a UseCounter for CustomScrollbar

Add a UseCounter for CustomScrollbar

This CL adds histogram statistics for the following
CustomScrollbar-related CSS selectors.

- CSSSelectorPseudoScrollbar
- CSSSelectorPseudoScrollbarButton
- CSSSelectorPseudoScrollbarThumb
- CSSSelectorPseudoScrollbarTrack
- CSSSelectorPseudoScrollbarTrackPiece

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=184820

[MuVen, 2014-10-31 11:20:49]

Patchset #1 (id:1) has been deleted

[MuVen, 2014-10-31 11:20:57]

Patchset #1 (id:20001) has been deleted

[MuVen, 2014-10-31 12:09:58]

sataya.m@samsung.com changed reviewers:
+ enne@chromium.org, esprehn@chromium.org

[MuVen, 2014-10-31 12:09:59]

PTAL.

[esprehn, 2014-10-31 17:21:22]

This seems fine, but note that most Google properties use custom scrollbar so
the number is going to be pretty high, I doubt we can remove it.

lgtm

https://codereview.chromium.org/693803002/diff/40001/Source/core/rendering/Re...
File Source/core/rendering/RenderScrollbarPart.cpp (right):

https://codereview.chromium.org/693803002/diff/40001/Source/core/rendering/Re...
Source/core/rendering/RenderScrollbarPart.cpp:49: static void
recordScrollbarPartStats(Document* document, ScrollbarPart part)
This should take the document reference instead of all the *document below.

[MuVen, 2014-11-04 05:20:47]

The CQ bit was checked by sataya.m@samsung.com

[commit-bot: I haz the power, 2014-11-04 05:21:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/693803002/60001

[commit-bot: I haz the power, 2014-11-04 05:21:58]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-11-04 05:21:58]

Failed to apply patch for Source/core/frame/UseCounter.h:
While running patch -p1 --forward --force --no-backup-if-mismatch;
  patching file Source/core/frame/UseCounter.h
  Hunk #1 FAILED at 546.
  1 out of 1 hunk FAILED -- saving rejects to file
Source/core/frame/UseCounter.h.rej

Patch:       Source/core/frame/UseCounter.h
Index: Source/core/frame/UseCounter.h
diff --git a/Source/core/frame/UseCounter.h b/Source/core/frame/UseCounter.h
index
84b13b4f05d46b80baf100cf85bf8fea904b67b0..da317bc0314ca5017277f47199968769b5e65786
100644
--- a/Source/core/frame/UseCounter.h
+++ b/Source/core/frame/UseCounter.h
@@ -546,6 +546,11 @@ public:
         WindowPostMessageWithLegacyTargetOriginArgument = 575,
         RenderRuby = 576,
         CanvasRenderingContext2DCompositeOperationDarker = 577,
+        CSSSelectorPseudoScrollbar = 578,
+        CSSSelectorPseudoScrollbarButton = 579,
+        CSSSelectorPseudoScrollbarThumb = 580,
+        CSSSelectorPseudoScrollbarTrack = 581,
+        CSSSelectorPseudoScrollbarTrackPiece = 582,
 
         // Add new features immediately above this line. Don't change assigned
         // numbers of any item, and don't reuse removed slots.

[MuVen, 2014-11-04 05:34:10]

The CQ bit was checked by sataya.m@samsung.com

[commit-bot: I haz the power, 2014-11-04 05:34:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/693803002/80001

[commit-bot: I haz the power, 2014-11-04 06:39:12]

Committed patchset #3 (id:80001) as 184820