Implement overlay scrollbar fade out for non-composited scrollers.

[Reland] Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098, 662402
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Committed: https://crrev.com/60d2bbbc8fa4cce01bbd90c97d3e989a47d6dedf
Committed: https://crrev.com/eb757fdbd63242a73f3074e4a50742d08d6ea488
Cr-Original-Original-Commit-Position: refs/heads/master@{#429616}
Cr-Original-Commit-Position: refs/heads/master@{#430065}
Cr-Commit-Position: refs/heads/master@{#431466}

[bokan, 2016-11-01 00:14:18]

Description was changed from

==========
Implement overlay scrollbar fade out for non-composited scrollers.

BUG=592098
==========

to

==========
Implement overlay scrollbar fade out for non-composited scrollers.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[bokan, 2016-11-01 00:14:51]

The CQ bit was checked by bokan@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-01 00:15:30]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-01 00:55:56]

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

[commit-bot: I haz the power, 2016-11-01 00:55:57]

Dry run: Try jobs failed on following builders:
  win_chromium_compile_dbg_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_comp...)

[bokan, 2016-11-01 01:51:46]

The CQ bit was checked by bokan@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-01 01:51:59]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-01 02:39:34]

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

[commit-bot: I haz the power, 2016-11-01 02:39:34]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[bokan, 2016-11-02 00:45:36]

The CQ bit was checked by bokan@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-02 00:46:10]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[bokan, 2016-11-02 01:05:31]

Description was changed from

==========
Implement overlay scrollbar fade out for non-composited scrollers.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as disabled which makes them invisible to
hit testing. In addition, I've changed the overlay scrollbar painting code to
not paint disabled scrollbars.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[bokan, 2016-11-02 01:08:23]

bokan@chromium.org changed reviewers:
+ pkasting@chromium.org

[bokan, 2016-11-02 01:08:24]

pkasting@: You have some context in this work now, mind taking a first look?

[commit-bot: I haz the power, 2016-11-02 01:13:29]

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

[commit-bot: I haz the power, 2016-11-02 01:13:29]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[Peter Kasting, 2016-11-02 01:58:47]

On 2016/11/02 01:08:24, bokan wrote:
> pkasting@: You have some context in this work now, mind taking a first look?

I'm not a Source/platform reviewer, and barely qualify as a Source/core one (I'm
about 99% Chrome-side developer).  Since it seems like this is almost entirely
Blink code, it would probably make more sense to get a reviewer who had worked
on scrolling/scrollbar stuff in Blink (maybe skobes?  Or check blame)

[bokan, 2016-11-02 11:39:27]

bokan@chromium.org changed reviewers:
+ skobes@chromium.org

[bokan, 2016-11-02 11:43:34]

On 2016/11/02 01:58:47, Peter Kasting wrote:
> On 2016/11/02 01:08:24, bokan wrote:
> > pkasting@: You have some context in this work now, mind taking a first look?
> 
> I'm not a Source/platform reviewer, and barely qualify as a Source/core one
(I'm
> about 99% Chrome-side developer).  Since it seems like this is almost entirely
> Blink code, it would probably make more sense to get a reviewer who had worked
> on scrolling/scrollbar stuff in Blink (maybe skobes?  Or check blame)

Ok, thanks. There isn't a really great Source/platform reviewer for scroll so
+skobes@ for general changes and I'll add OWNERs after. pkasting@, would you
mind stamping for ui/native_theme?

[bokan, 2016-11-02 14:07:38]

The CQ bit was checked by bokan@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-02 14:08:00]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-02 15:33:30]

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

[commit-bot: I haz the power, 2016-11-02 15:33:31]

Dry run: This issue passed the CQ dry run.

[dtapuska, 2016-11-02 16:53:20]

dtapuska@chromium.org changed reviewers:
+ dtapuska@chromium.org

[dtapuska, 2016-11-02 16:53:21]

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/paint/PaintLayer.cpp (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/paint/PaintLayer.cpp:810:
m_scrollableArea->visibleContentResized();
I fear you have a re-entry problem here. You are notifying an observer in the
middle of what should be an atomic operation.

Can we call visibleContentResized() after we've assigned m_size ? Or perhaps
even better at the bottom of this method?

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/scroll/Scrollbar.h (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/scroll/Scrollbar.h:108: void
setScrollbarsHidden(bool) override;
Personally I'd prefer if this was a positive affirmation like
setScrollbarsVisible(bool). But it could just by my mental model.

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/scroll/ScrollbarThemeMac.mm (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/scroll/ScrollbarThemeMac.mm:95:
_scrollbar->setScrollbarsHidden(!visible);
Can we remove the _visible member now?

[Peter Kasting, 2016-11-02 16:56:56]

ui/native_theme/ LGTM

[skobes, 2016-11-02 21:02:44]

Nice work, mostly nits. :)

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Layo...
File third_party/WebKit/LayoutTests/plugins/overlay-scrollbar-mouse-capture.html
(right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Layo...
third_party/WebKit/LayoutTests/plugins/overlay-scrollbar-mouse-capture.html:59:
// RuntimeEnabledFeature after the ScrollbarTheme is initialized. It
Ew. :(  Are all layout tests that use setOverlayScrollbarsEnabled broken in this
manner?  If so we should fix that or remove it from InternalSettings.

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h:298: void
visibleContentResized();
"visibleSizeChanged" might be clearer.

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/scroll/ScrollableArea.h (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/scroll/ScrollableArea.h:354: void
fadeOverlayScrollbarsTimerFired(TimerBase*);
Can this be private?

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/scroll/Scrollbar.cpp (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/scroll/Scrollbar.cpp:465: bool isCaptured =
m_pressedPart == ThumbPart;
Does this work if the mouse is pressed on the thumb but then moves off of the
thumb before being released?

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/scroll/Scrollbar.h (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/scroll/Scrollbar.h:108: void
setScrollbarsHidden(bool) override;
On 2016/11/02 16:53:21, dtapuska wrote:
> Personally I'd prefer if this was a positive affirmation like
> setScrollbarsVisible(bool). But it could just by my mental model.

I prefer setScrollbarsHidden for consistency with other plumbing like
Settings::hideScrollbars().  Unless you're going to change it everywhere.

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/scroll/ScrollbarTheme.cpp (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/scroll/ScrollbarTheme.cpp:238: #if
!OS(MACOSX)
Override in ScrollbarThemeMac instead of using #if's.

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/scroll/ScrollbarThemeOverlay.cpp
(right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/scroll/ScrollbarThemeOverlay.cpp:170: if
(!scrollbar.enabled())
Move this up next to the rest of the "state = " logic.

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/web/tests/WebFrameTest.cpp (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/web/tests/WebFrameTest.cpp:10376: "<!DOCTYPE html>"
For a large block like this a 4-space indent seems more sensible than aligning
to the ( .

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/publ...
File third_party/WebKit/public/platform/WebThemeEngine.h (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/publ...
third_party/WebKit/public/platform/WebThemeEngine.h:168: virtual double
getOverlayScrollbarFadeOutDelaySeconds() { return 0.0; }
Could these just be fields in ScrollbarStyle and reuse getOverlayScrollbarStyle?

https://codereview.chromium.org/2467693002/diff/80001/ui/native_theme/native_...
File ui/native_theme/native_theme_aura.cc (right):

https://codereview.chromium.org/2467693002/diff/80001/ui/native_theme/native_...
ui/native_theme/native_theme_aura.cc:200: if (state == kDisabled)
This seems redundant with an identical check at the top of the function.

[bokan, 2016-11-02 22:41:57]

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Layo...
File third_party/WebKit/LayoutTests/plugins/overlay-scrollbar-mouse-capture.html
(right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Layo...
third_party/WebKit/LayoutTests/plugins/overlay-scrollbar-mouse-capture.html:59:
// RuntimeEnabledFeature after the ScrollbarTheme is initialized. It
On 2016/11/02 21:02:43, skobes wrote:
> Ew. :(  Are all layout tests that use setOverlayScrollbarsEnabled broken in
this
> manner?  If so we should fix that or remove it from InternalSettings.

Yup, there's already a TODO for this in InternalSettings:

  // FIXME: The following are RuntimeEnabledFeatures and likely
  // cannot be changed after process start. These setters should
  // be removed or moved onto internals.runtimeFlags:

I agree we should fix this but it's out of scope for this patch. There's a few
folks in WAT currently working on scrollbar stuff so I'll make sure we actually
get it done - filed crbug.com/661783

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/paint/PaintLayer.cpp (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/paint/PaintLayer.cpp:810:
m_scrollableArea->visibleContentResized();
On 2016/11/02 16:53:21, dtapuska wrote:
> I fear you have a re-entry problem here. You are notifying an observer in the
> middle of what should be an atomic operation.
> 
> Can we call visibleContentResized() after we've assigned m_size ? Or perhaps
> even better at the bottom of this method?

Good catch, I'll add it to the bottom.

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h:298: void
visibleContentResized();
On 2016/11/02 21:02:43, skobes wrote:
> "visibleSizeChanged" might be clearer.

Thanks, done.

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/scroll/Scrollbar.cpp (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/scroll/Scrollbar.cpp:465: bool isCaptured =
m_pressedPart == ThumbPart;
On 2016/11/02 21:02:43, skobes wrote:
> Does this work if the mouse is pressed on the thumb but then moves off of the
> thumb before being released?

Yes, there's a bunch of logic in EventHandler for this though it's not great and
I found some edge cases but we'll fix those separately. The basic usage works as
you'd expect.

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/scroll/Scrollbar.h (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/scroll/Scrollbar.h:108: void
setScrollbarsHidden(bool) override;
On 2016/11/02 21:02:43, skobes wrote:
> On 2016/11/02 16:53:21, dtapuska wrote:
> > Personally I'd prefer if this was a positive affirmation like
> > setScrollbarsVisible(bool). But it could just by my mental model.

I preferred |hidden| to |visible| since visible is the default state and we
really are "hiding" them from hit testing. That said, I don't feel strongly
about it but if we do decide to change it should happen after this patch as
there's lots of plumbing in CC as well.

> I prefer setScrollbarsHidden for consistency with other plumbing like
> Settings::hideScrollbars().  Unless you're going to change it everywhere.

Huh, didn't even know about that setting. It "hides" scrollbars by not creating
them which is different from the flag I added, perhaps we should rename it to
"NoScrollbars" or something more like that?

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/scroll/ScrollbarTheme.cpp (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/scroll/ScrollbarTheme.cpp:238: #if
!OS(MACOSX)
On 2016/11/02 21:02:43, skobes wrote:
> Override in ScrollbarThemeMac instead of using #if's.

Can't since WebThemeEngine.h is conditionally included in this file but I've
moved the themeEngine bits into ScrollbarThemeOverlay.

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/scroll/ScrollbarThemeMac.mm (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/scroll/ScrollbarThemeMac.mm:95:
_scrollbar->setScrollbarsHidden(!visible);
On 2016/11/02 16:53:21, dtapuska wrote:
> Can we remove the _visible member now?

Done.

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/platform/scroll/ScrollbarThemeOverlay.cpp
(right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/platform/scroll/ScrollbarThemeOverlay.cpp:170: if
(!scrollbar.enabled())
On 2016/11/02 21:02:43, skobes wrote:
> Move this up next to the rest of the "state = " logic.

Done.

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/web/tests/WebFrameTest.cpp (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/web/tests/WebFrameTest.cpp:10376: "<!DOCTYPE html>"
On 2016/11/02 21:02:43, skobes wrote:
> For a large block like this a 4-space indent seems more sensible than aligning
> to the ( .

Unfortunately, this is git cl format's doing so I'd have to bypass checks and
next time someone touches it they'll get the same.

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/publ...
File third_party/WebKit/public/platform/WebThemeEngine.h (right):

https://codereview.chromium.org/2467693002/diff/80001/third_party/WebKit/publ...
third_party/WebKit/public/platform/WebThemeEngine.h:168: virtual double
getOverlayScrollbarFadeOutDelaySeconds() { return 0.0; }
On 2016/11/02 21:02:43, skobes wrote:
> Could these just be fields in ScrollbarStyle and reuse
getOverlayScrollbarStyle?

Yup, done. I also added a TODO to set those members for Android so we can get
the same behavior for non-composited scrollers in Android. That'll require some
plumbing to move the constants into a single place so I'll leave that for a
future patch.

https://codereview.chromium.org/2467693002/diff/80001/ui/native_theme/native_...
File ui/native_theme/native_theme_aura.cc (right):

https://codereview.chromium.org/2467693002/diff/80001/ui/native_theme/native_...
ui/native_theme/native_theme_aura.cc:200: if (state == kDisabled)
On 2016/11/02 21:02:43, skobes wrote:
> This seems redundant with an identical check at the top of the function.

Doh! Missed that :)

[skobes, 2016-11-02 23:46:43]

lgtm w/ nit

https://codereview.chromium.org/2467693002/diff/100001/content/child/webtheme...
File content/child/webthemeengine_impl_default.cc (right):

https://codereview.chromium.org/2467693002/diff/100001/content/child/webtheme...
content/child/webthemeengine_impl_default.cc:248: style->fadeOutDelaySeconds =
ui::kOverlayScrollbarFadeOutDelay.InSecondsF();
2-space indent

[bokan, 2016-11-02 23:52:54]

bokan@chromium.org changed reviewers:
+ jbroman@chromium.org, piman@chromium.org, rbyers@chromium.org

[bokan, 2016-11-02 23:52:55]

rbyers@ for public/platform
jbroman@ for Source/platform
+piman@ for content/child

[Rick Byers, 2016-11-03 00:20:02]

On 2016/11/02 23:52:55, bokan wrote:
> rbyers@ for public/platform

public/platform LGTM

> jbroman@ for Source/platform
> +piman@ for content/child

[piman, 2016-11-03 00:42:03]

lgtm

[bokan, 2016-11-03 13:04:39]

The CQ bit was checked by bokan@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-03 13:04:57]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[dtapuska, 2016-11-03 14:17:49]

On 2016/11/03 00:42:03, piman wrote:
> lgtm

lgtm

[bokan, 2016-11-03 14:22:37]

Description was changed from

==========
Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as disabled which makes them invisible to
hit testing. In addition, I've changed the overlay scrollbar painting code to
not paint disabled scrollbars.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[jbroman, 2016-11-03 14:22:45]

platform rs lgtm

[commit-bot: I haz the power, 2016-11-03 14:54:42]

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

[commit-bot: I haz the power, 2016-11-03 14:54:43]

Dry run: Try jobs failed on following builders:
  win_chromium_rel_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[bokan, 2016-11-03 14:56:25]

The CQ bit was checked by bokan@chromium.org

[bokan, 2016-11-03 14:56:26]

The patchset sent to the CQ was uploaded after l-g-t-m from
pkasting@chromium.org, skobes@chromium.org
Link to the patchset: https://codereview.chromium.org/2467693002/#ps120001
(title: "Nit")

[commit-bot: I haz the power, 2016-11-03 14:56:56]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-03 16:41:51]

Description was changed from

==========
Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[commit-bot: I haz the power, 2016-11-03 16:41:53]

Committed patchset #7 (id:120001)

[commit-bot: I haz the power, 2016-11-03 17:12:57]

Description was changed from

==========
Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Cr-Commit-Position: refs/heads/master@{#429616}
==========

[commit-bot: I haz the power, 2016-11-03 17:12:58]

Patchset 7 (id:??) landed as
https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Cr-Commit-Position: refs/heads/master@{#429616}

[tapted, 2016-11-04 01:54:31]

tapted@chromium.org changed reviewers:
+ tapted@chromium.org

[tapted, 2016-11-04 01:54:32]

Sorry - need to revert for some MSAN errors

see 

https://storage.googleapis.com/chromium-layout-test-archives/WebKit_Linux_Pre...

https://codereview.chromium.org/2467693002/diff/120001/third_party/WebKit/Sou...
File third_party/WebKit/Source/platform/scroll/ScrollableArea.cpp (right):

https://codereview.chromium.org/2467693002/diff/120001/third_party/WebKit/Sou...
third_party/WebKit/Source/platform/scroll/ScrollableArea.cpp:569: if
(!timeUntilDisable)
STDERR: ==4==WARNING: MemorySanitizer: use-of-uninitialized-value
STDERR:     #0 0xafdca9e in showOverlayScrollbars
third_party/WebKit/Source/platform/scroll/ScrollableArea.cpp:569:7
STDERR:     #1 0xafdd69b in contentsResized
third_party/WebKit/Source/platform/scroll/ScrollableArea.cpp:386:3
STDERR:     #2 0xd4b2510 in contentsResized
third_party/WebKit/Source/core/frame/FrameView.cpp:1918:19
STDERR:     #3 0xb55db39 in updateMainFrameLayoutSize
third_party/WebKit/Source/web/WebViewImpl.cpp:3348:9
STDERR:     #4 0xb55c501 in updatePageDefinedViewportConstraints
third_party/WebKit/Source/web/WebViewImpl.cpp:3329:3
STDERR:     #5 0xcb14429 in updateViewportDescription
third_party/WebKit/Source/core/dom/Document.cpp:3400:33
STDERR:     #6 0xea97010 in settingsChanged
third_party/WebKit/Source/core/page/Page.cpp:344:49
STDERR:     #7 0xb5edffa in enableMobileEmulation
third_party/WebKit/Source/web/DevToolsEmulator.cpp:269:37
STDERR:     #8 0xb5ed92f in enableDeviceEmulation
third_party/WebKit/Source/web/DevToolsEmulator.cpp:218:5
STDERR:     #9 0xa96ffa2 in Apply
content/renderer/devtools/render_widget_screen_metrics_emulator.cc:143:14
STDERR:     #10 0xa57e889 in OnEnableDeviceEmulation
content/renderer/render_widget.cc:626:31
STDERR:     #11 0xa57dfcd in DispatchToMethodImpl<content::RenderWidget *, void

[tapted, 2016-11-04 01:56:26]

A revert of this CL (patchset #7 id:120001) has been created in
https://codereview.chromium.org/2478463003/ by tapted@chromium.org.

The reason for reverting is: WebKit Linux Precise MSAN failing since
https://uberchromegw.corp.google.com/i/chromium.webkit/builders/WebKit%20Linu...

Errors like

STDERR: ==4==WARNING: MemorySanitizer: use-of-uninitialized-value
STDERR:     #0 0xafdca9e in showOverlayScrollbars
third_party/WebKit/Source/platform/scroll/ScrollableArea.cpp:569:7.

[Lei Zhang, 2016-11-04 02:03:01]

thestig@chromium.org changed reviewers:
+ thestig@chromium.org

[Lei Zhang, 2016-11-04 02:03:02]

https://codereview.chromium.org/2467693002/diff/120001/third_party/WebKit/Sou...
File third_party/WebKit/Source/platform/scroll/ScrollableArea.cpp (right):

https://codereview.chromium.org/2467693002/diff/120001/third_party/WebKit/Sou...
third_party/WebKit/Source/platform/scroll/ScrollableArea.cpp:569: if
(!timeUntilDisable)
On 2016/11/04 01:54:32, tapted wrote:
> STDERR: ==4==WARNING: MemorySanitizer: use-of-uninitialized-value
> STDERR:     #0 0xafdca9e in showOverlayScrollbars
> third_party/WebKit/Source/platform/scroll/ScrollableArea.cpp:569:7
> STDERR:     #1 0xafdd69b in contentsResized
> third_party/WebKit/Source/platform/scroll/ScrollableArea.cpp:386:3
> STDERR:     #2 0xd4b2510 in contentsResized
> third_party/WebKit/Source/core/frame/FrameView.cpp:1918:19
> STDERR:     #3 0xb55db39 in updateMainFrameLayoutSize
> third_party/WebKit/Source/web/WebViewImpl.cpp:3348:9
> STDERR:     #4 0xb55c501 in updatePageDefinedViewportConstraints
> third_party/WebKit/Source/web/WebViewImpl.cpp:3329:3
> STDERR:     #5 0xcb14429 in updateViewportDescription
> third_party/WebKit/Source/core/dom/Document.cpp:3400:33
> STDERR:     #6 0xea97010 in settingsChanged
> third_party/WebKit/Source/core/page/Page.cpp:344:49
> STDERR:     #7 0xb5edffa in enableMobileEmulation
> third_party/WebKit/Source/web/DevToolsEmulator.cpp:269:37
> STDERR:     #8 0xb5ed92f in enableDeviceEmulation
> third_party/WebKit/Source/web/DevToolsEmulator.cpp:218:5
> STDERR:     #9 0xa96ffa2 in Apply
> content/renderer/devtools/render_widget_screen_metrics_emulator.cc:143:14
> STDERR:     #10 0xa57e889 in OnEnableDeviceEmulation
> content/renderer/render_widget.cc:626:31
> STDERR:     #11 0xa57dfcd in DispatchToMethodImpl<content::RenderWidget *,
void 

Uninitialized value was created by an allocation of 'style' in the stack frame
of function
'_ZNK5blink21ScrollbarThemeOverlay38overlayScrollbarFadeOutDurationSecondsEv'
#0 0xaffd700 in ??
third_party/WebKit/Source/platform/scroll/ScrollbarThemeOverlay.cpp:81:0

[tapted, 2016-11-04 06:16:33]

See http://crbug.com/662147 for additional info.

[tapted, 2016-11-04 06:16:51]

Description was changed from

==========
Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Cr-Commit-Position: refs/heads/master@{#429616}
==========

to

==========
Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Cr-Commit-Position: refs/heads/master@{#429616}
==========

[tapted, 2016-11-04 06:16:51]

tapted@chromium.org changed reviewers:
- tapted@chromium.org

[bokan, 2016-11-04 15:00:31]

The CQ bit was checked by bokan@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-04 15:00:46]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[bokan, 2016-11-04 15:08:33]

Description was changed from

==========
Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Cr-Commit-Position: refs/heads/master@{#429616}
==========

to

==========
[Reland] Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Cr-Commit-Position: refs/heads/master@{#429616}
==========

[commit-bot: I haz the power, 2016-11-04 16:16:37]

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

[commit-bot: I haz the power, 2016-11-04 16:16:38]

Dry run: This issue passed the CQ dry run.

[bokan, 2016-11-04 17:59:01]

Ok, the issue was that tests were using a Mock WebThemeEngine I didn't find
until now so the fade out delays were uninitialized by the default
getOverlayScrollbarStyle in WebThemeEngine. This was causing use to try posting
a Blink task with random values. Additionally, Android does implement that
method but I didn't initialize these values there either. The latest patch
initializes these values in the default WebThemeEngine implementation and zeroes
them out in the Android version.

Interestingly, I ran the MSAN bot on the old patch and it passed. I did
reproduce the MSAN failure locally and confirmed the latest patch fixes it. I'm
going to reland since the changes are trivial. I'll monitor the waterfall for
breakage.

[bokan, 2016-11-04 18:01:15]

The CQ bit was checked by bokan@chromium.org

[bokan, 2016-11-04 18:01:16]

The patchset sent to the CQ was uploaded after l-g-t-m from skobes@chromium.org,
jbroman@chromium.org, rbyers@chromium.org, piman@chromium.org,
pkasting@chromium.org, dtapuska@chromium.org
Link to the patchset: https://codereview.chromium.org/2467693002/#ps180001
(title: "Make sure fade out times are always initialized")

[commit-bot: I haz the power, 2016-11-04 18:02:16]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-04 18:16:09]

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

[commit-bot: I haz the power, 2016-11-04 18:16:10]

Try jobs failed on following builders:
  cast_shell_android on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/cast_shell_a...)
  blimp_linux_dbg on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/blimp_linux_dbg...)
  chromeos_amd64-generic_chromium_compile_only_ng on
master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromeos_amd64-...)

[bokan, 2016-11-04 20:37:41]

The CQ bit was checked by bokan@chromium.org

[bokan, 2016-11-04 20:37:42]

The patchset sent to the CQ was uploaded after l-g-t-m from skobes@chromium.org,
jbroman@chromium.org, rbyers@chromium.org, piman@chromium.org,
pkasting@chromium.org, dtapuska@chromium.org
Link to the patchset: https://codereview.chromium.org/2467693002/#ps200001
(title: "Build fix")

[commit-bot: I haz the power, 2016-11-04 20:38:26]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-04 23:27:15]

Description was changed from

==========
[Reland] Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Cr-Commit-Position: refs/heads/master@{#429616}
==========

to

==========
[Reland] Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Cr-Commit-Position: refs/heads/master@{#429616}
==========

[commit-bot: I haz the power, 2016-11-04 23:27:20]

Committed patchset #11 (id:200001)

[commit-bot: I haz the power, 2016-11-04 23:30:10]

Description was changed from

==========
[Reland] Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Cr-Commit-Position: refs/heads/master@{#429616}
==========

to

==========
[Reland] Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Committed: https://crrev.com/60d2bbbc8fa4cce01bbd90c97d3e989a47d6dedf
Cr-Original-Commit-Position: refs/heads/master@{#429616}
Cr-Commit-Position: refs/heads/master@{#430065}
==========

[commit-bot: I haz the power, 2016-11-04 23:30:12]

Patchset 11 (id:??) landed as
https://crrev.com/60d2bbbc8fa4cce01bbd90c97d3e989a47d6dedf
Cr-Commit-Position: refs/heads/master@{#430065}

[bokan, 2016-11-08 21:43:23]

A revert of this CL (patchset #11 id:200001) has been created in
https://codereview.chromium.org/2489703002/ by bokan@chromium.org.

The reason for reverting is: Speculative revert for issue crbug.com/662402

BUG=662402.

[bokan, 2016-11-09 22:21:48]

Description was changed from

==========
[Reland] Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Committed: https://crrev.com/60d2bbbc8fa4cce01bbd90c97d3e989a47d6dedf
Cr-Original-Commit-Position: refs/heads/master@{#429616}
Cr-Commit-Position: refs/heads/master@{#430065}
==========

to

==========
[Reland] Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Committed: https://crrev.com/60d2bbbc8fa4cce01bbd90c97d3e989a47d6dedf
Cr-Original-Commit-Position: refs/heads/master@{#429616}
Cr-Commit-Position: refs/heads/master@{#430065}
==========

[bokan, 2016-11-10 22:03:00]

Turns out the problem was that I forgot to remove the code that updates enabled
state on visibility change. This code was originally how I avoided hit testing
invisible scollbars but since moved to use the Mac path of
Scrollbar::shouldParticipateInHitTesting - forgetting to remove the old bits.
The enable/disable in FrameView was set from updateScrollbarGeometry which was
causing frequent invalidations, paints and commits on each frame.

[bokan, 2016-11-10 22:03:21]

The CQ bit was checked by bokan@chromium.org

[bokan, 2016-11-10 22:03:21]

The patchset sent to the CQ was uploaded after l-g-t-m from skobes@chromium.org,
jbroman@chromium.org, rbyers@chromium.org, piman@chromium.org,
pkasting@chromium.org, dtapuska@chromium.org
Link to the patchset: https://codereview.chromium.org/2467693002/#ps220001
(title: "Fixed crash and perf issues on Mac   Rebase")

[commit-bot: I haz the power, 2016-11-10 22:04:07]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[bokan, 2016-11-10 22:05:11]

Description was changed from

==========
[Reland] Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Committed: https://crrev.com/60d2bbbc8fa4cce01bbd90c97d3e989a47d6dedf
Cr-Original-Commit-Position: refs/heads/master@{#429616}
Cr-Commit-Position: refs/heads/master@{#430065}
==========

to

==========
[Reland] Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098, 662402
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Committed: https://crrev.com/60d2bbbc8fa4cce01bbd90c97d3e989a47d6dedf
Cr-Original-Commit-Position: refs/heads/master@{#429616}
Cr-Commit-Position: refs/heads/master@{#430065}
==========

[bokan, 2016-11-10 23:40:10]

The CQ bit was unchecked by bokan@chromium.org

[bokan, 2016-11-11 00:37:37]

The CQ bit was checked by bokan@chromium.org

[bokan, 2016-11-11 00:37:38]

The patchset sent to the CQ was uploaded after l-g-t-m from skobes@chromium.org,
jbroman@chromium.org, rbyers@chromium.org, piman@chromium.org,
pkasting@chromium.org, dtapuska@chromium.org
Link to the patchset: https://codereview.chromium.org/2467693002/#ps240001
(title: "Forgot to update tests")

[commit-bot: I haz the power, 2016-11-11 00:37:58]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-11 00:47:07]

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

[commit-bot: I haz the power, 2016-11-11 00:47:09]

Try jobs failed on following builders:
  chromium_presubmit on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[bokan, 2016-11-11 00:54:03]

The CQ bit was checked by bokan@chromium.org

[bokan, 2016-11-11 00:54:04]

The patchset sent to the CQ was uploaded after l-g-t-m from skobes@chromium.org,
jbroman@chromium.org, rbyers@chromium.org, piman@chromium.org,
pkasting@chromium.org, dtapuska@chromium.org
Link to the patchset: https://codereview.chromium.org/2467693002/#ps260001
(title: "sigh....git cl format")

[commit-bot: I haz the power, 2016-11-11 00:54:35]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-11 02:27:42]

Description was changed from

==========
[Reland] Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098, 662402
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Committed: https://crrev.com/60d2bbbc8fa4cce01bbd90c97d3e989a47d6dedf
Cr-Original-Commit-Position: refs/heads/master@{#429616}
Cr-Commit-Position: refs/heads/master@{#430065}
==========

to

==========
[Reland] Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098, 662402
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Committed: https://crrev.com/60d2bbbc8fa4cce01bbd90c97d3e989a47d6dedf
Cr-Original-Commit-Position: refs/heads/master@{#429616}
Cr-Commit-Position: refs/heads/master@{#430065}
==========

[commit-bot: I haz the power, 2016-11-11 02:27:44]

Committed patchset #14 (id:260001)

[commit-bot: I haz the power, 2016-11-11 02:32:04]

Description was changed from

==========
[Reland] Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098, 662402
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Committed: https://crrev.com/60d2bbbc8fa4cce01bbd90c97d3e989a47d6dedf
Cr-Original-Commit-Position: refs/heads/master@{#429616}
Cr-Commit-Position: refs/heads/master@{#430065}
==========

to

==========
[Reland] Implement overlay scrollbar fade out for non-composited scrollers.

In crrev.com/2442573002 and crrev.com/2453553003 I added fade out for Aura
overlay scrollbars. In this patch I add a simple instantly disappearing
fade-out for scrollers that aren't composited.

The changes in this patch are:

-Plumb through the fade out durations into Blink. Any time a ScrollableArea is
scrolled or resized we show the scrollbars and start a timer to make them
disappear. The scrollbars are marked as "hidden" and made disabled and invisible
to hit testing.

-Fixed hit testing for overlay scrollbars so we can't scroll by clicking on the
track (which isn't painted).

-Fixed two layout tests:
  third_party/WebKit/LayoutTests/fast/scrolling/scrollbar-tickmarks-hittest.html
  overlay-scrollbar-mouse-capture.html
  These tests turn on overlay scrollbars but try to scroll by clicking a
  button/track which I fixed. The tests now drag the thumb instead.

-In crrev.com/2453553003 I added didChangeScrollbarsHidden to disable overlay
scrollbars so they're invisible to hit testing. It turns out Mac overlay
scrollbars already have this functionality in
ScrollableArea::scrollbarVisibilityChanged and
Scrollbar::shouldParticipateInHitTesting so I removed didChangeScrollbarsHidden
and used these. I also removed some redundancy in the Mac path so that Mac and
Aura overlays disable hit testing in the same way.

-Removed the static compile assert about ScrollableArea staying small. There's
no reason ScrollableArea is particularily special and this encourages
developers to duplicate functionality in the descendant classes.

BUG=592098, 662402
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4430234f2f5f52efe60ad2b8e6608112352259da
Committed: https://crrev.com/60d2bbbc8fa4cce01bbd90c97d3e989a47d6dedf
Committed: https://crrev.com/eb757fdbd63242a73f3074e4a50742d08d6ea488
Cr-Original-Original-Commit-Position: refs/heads/master@{#429616}
Cr-Original-Commit-Position: refs/heads/master@{#430065}
Cr-Commit-Position: refs/heads/master@{#431466}
==========

[commit-bot: I haz the power, 2016-11-11 02:32:06]

Patchset 14 (id:??) landed as
https://crrev.com/eb757fdbd63242a73f3074e4a50742d08d6ea488
Cr-Commit-Position: refs/heads/master@{#431466}