The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a9783e125f7390062fb6b574e05923a24b4737db

commit a9783e125f7390062fb6b574e05923a24b4737db
Author: Sandra Sun <sunyunjia@chromium.org>
Date: Tue Dec 05 21:43:33 2017

Snap at GestureScrollEnd on main thread.

As the first step of ScrollSnapPoints, this patch implements it on main
thread at GestureScrollEnd. It introduces necessary data structures:
SnapAreaData and SnapContainerData, updates the data after style change
and layout, implements a naive algorithm to select snap points at
intended-end-position, adds unit-tests for logic and adds sim-tests for
behavior.

Bug:  778257 
Change-Id: I307d51254bd9ab9b7a42b0614d181adac662fa47
Reviewed-on: https://chromium-review.googlesource.com/756887
Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Reviewed-by: Darren Shen <shend@chromium.org>
Reviewed-by: David Bokan <bokan@chromium.org>
Reviewed-by: Majid Valipour <majidvp@chromium.org>
Commit-Queue: Sandra Sun <sunyunjia@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521840}
[modify] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/core/BUILD.gn
[modify] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/core/css/CSSProperties.json5
[modify] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/core/css/properties/longhands/ScrollSnapMarginSide.cpp
[modify] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/core/frame/LocalFrameView.cpp
[modify] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/core/input/ScrollManager.cpp
[modify] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/core/input/ScrollManager.h
[add] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/core/input/ScrollSnapTest.cpp
[modify] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/core/layout/LayoutBox.cpp
[modify] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/core/layout/LayoutBox.h
[modify] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.cpp
[modify] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.h
[modify] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/core/page/scrolling/SnapCoordinatorTest.cpp
[modify] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/core/style/BUILD.gn
[modify] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/core/style/ComputedStyleConstants.h
[delete] https://crrev.com/5a5f8f946ebd6ae2057ed14edc3d13e2290db36e/third_party/WebKit/Source/core/style/ScrollSnap.h
[modify] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/platform/BUILD.gn
[add] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/platform/scroll/ScrollSnapData.cpp
[add] https://crrev.com/a9783e125f7390062fb6b574e05923a24b4737db/third_party/WebKit/Source/platform/scroll/ScrollSnapData.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/38cf25608787430aabe28bb4d156d20521a92641

commit 38cf25608787430aabe28bb4d156d20521a92641
Author: Ojan Vafai <ojan@chromium.org>
Date: Wed Dec 06 00:59:42 2017

Revert "Snap at GestureScrollEnd on main thread."

This reverts commit a9783e125f7390062fb6b574e05923a24b4737db.

Reason for revert: Broke webkit_unit_tests

All/SnapCoordinatorTest.OverflowedSnapPositionCalculation/1
All/SnapCoordinatorTest.OverflowedSnapPositionCalculation/0
All/SnapCoordinatorTest.EndAlignmentCalculation/1
All/SnapCoordinatorTest.CenterAlignmentCalculation/0
All/SnapCoordinatorTest.CenterAlignmentCalculation/1
All/SnapCoordinatorTest.EndAlignmentCalculation/0
All/SnapCoordinatorTest.StartAlignmentCalculation/0
All/SnapCoordinatorTest.StartAlignmentCalculation/1
All/SnapCoordinatorTest.NegativeMarginStartAlignmentCalculation/1
All/SnapCoordinatorTest.NegativeMarginStartAlignmentCalculation/0
All/SnapCoordinatorTest.AsymmetricalCenterAlignmentCalculation/1
All/SnapCoordinatorTest.AsymmetricalCenterAlignmentCalculation/0

https://uberchromegw.corp.google.com/i/chromium.webkit/builders/WebKit%20Android%20%28Nexus4%29/builds/72004

Original change's description:
> Snap at GestureScrollEnd on main thread.
> 
> As the first step of ScrollSnapPoints, this patch implements it on main
> thread at GestureScrollEnd. It introduces necessary data structures:
> SnapAreaData and SnapContainerData, updates the data after style change
> and layout, implements a naive algorithm to select snap points at
> intended-end-position, adds unit-tests for logic and adds sim-tests for
> behavior.
> 
> Bug:  778257 
> Change-Id: I307d51254bd9ab9b7a42b0614d181adac662fa47
> Reviewed-on: https://chromium-review.googlesource.com/756887
> Reviewed-by: Jeremy Roman <jbroman@chromium.org>
> Reviewed-by: Darren Shen <shend@chromium.org>
> Reviewed-by: David Bokan <bokan@chromium.org>
> Reviewed-by: Majid Valipour <majidvp@chromium.org>
> Commit-Queue: Sandra Sun <sunyunjia@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#521840}

TBR=bokan@chromium.org,jbroman@chromium.org,majidvp@chromium.org,sunyunjia@chromium.org,shend@chromium.org

Change-Id: I172b350063d66006a3974919f67c7d4f4f0a980d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug:  778257 
Reviewed-on: https://chromium-review.googlesource.com/809313
Reviewed-by: Ojan Vafai <ojan@chromium.org>
Commit-Queue: Ojan Vafai <ojan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521928}
[modify] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/core/BUILD.gn
[modify] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/core/css/CSSProperties.json5
[modify] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/core/css/properties/longhands/ScrollSnapMarginSide.cpp
[modify] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/core/frame/LocalFrameView.cpp
[modify] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/core/input/ScrollManager.cpp
[modify] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/core/input/ScrollManager.h
[delete] https://crrev.com/e7898d1ac109b4081cba963ea6c4aab9704ec135/third_party/WebKit/Source/core/input/ScrollSnapTest.cpp
[modify] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/core/layout/LayoutBox.cpp
[modify] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/core/layout/LayoutBox.h
[modify] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.cpp
[modify] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.h
[modify] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/core/page/scrolling/SnapCoordinatorTest.cpp
[modify] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/core/style/BUILD.gn
[modify] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/core/style/ComputedStyleConstants.h
[add] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/core/style/ScrollSnap.h
[modify] https://crrev.com/38cf25608787430aabe28bb4d156d20521a92641/third_party/WebKit/Source/platform/BUILD.gn
[delete] https://crrev.com/e7898d1ac109b4081cba963ea6c4aab9704ec135/third_party/WebKit/Source/platform/scroll/ScrollSnapData.cpp
[delete] https://crrev.com/e7898d1ac109b4081cba963ea6c4aab9704ec135/third_party/WebKit/Source/platform/scroll/ScrollSnapData.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/db77c44916a84b82327d64608bfb8ef2dc4ff090

commit db77c44916a84b82327d64608bfb8ef2dc4ff090
Author: Sandra Sun <sunyunjia@chromium.org>
Date: Wed Dec 06 19:18:03 2017

Reland "Snap at GestureScrollEnd on main thread."

The failure is likely caused by the scrollbar thickness varied across
platforms. So I use MaiximumScrollOffset as expected value in test.
This patch also check nullptr when getting ScrollableArea to fix a
clusterfuzz failure in the previous patch.

This is a reland of a9783e125f7390062fb6b574e05923a24b4737db
Original change's description:
> Snap at GestureScrollEnd on main thread.
>
> As the first step of ScrollSnapPoints, this patch implements it on main
> thread at GestureScrollEnd. It introduces necessary data structures:
> SnapAreaData and SnapContainerData, updates the data after style change
> and layout, implements a naive algorithm to select snap points at
> intended-end-position, adds unit-tests for logic and adds sim-tests for
> behavior.
>
> Bug:  778257 
> Change-Id: I307d51254bd9ab9b7a42b0614d181adac662fa47
> Reviewed-on: https://chromium-review.googlesource.com/756887
> Reviewed-by: Jeremy Roman <jbroman@chromium.org>
> Reviewed-by: Darren Shen <shend@chromium.org>
> Reviewed-by: David Bokan <bokan@chromium.org>
> Reviewed-by: Majid Valipour <majidvp@chromium.org>
> Commit-Queue: Sandra Sun <sunyunjia@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#521840}

TBR=bokan@chromium.org,jbroman@chromium.org,majidvp@chromium.org,shend@chromium.org

Bug:  778257 
Change-Id: I437e7491c4a98c8ecaa5b15124c48e97e60fa57a
Reviewed-on: https://chromium-review.googlesource.com/810059
Commit-Queue: Sandra Sun <sunyunjia@chromium.org>
Reviewed-by: Sandra Sun <sunyunjia@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522159}
[modify] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/core/BUILD.gn
[modify] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/core/css/CSSProperties.json5
[modify] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/core/css/properties/longhands/ScrollSnapMarginSide.cpp
[modify] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/core/frame/LocalFrameView.cpp
[modify] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/core/input/ScrollManager.cpp
[modify] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/core/input/ScrollManager.h
[add] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/core/input/ScrollSnapTest.cpp
[modify] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/core/layout/LayoutBox.cpp
[modify] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/core/layout/LayoutBox.h
[modify] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.cpp
[modify] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.h
[modify] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/core/page/scrolling/SnapCoordinatorTest.cpp
[modify] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/core/style/BUILD.gn
[modify] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/core/style/ComputedStyleConstants.h
[delete] https://crrev.com/26863ea2799fd936613d77f5fb3d0b69d83a6d8f/third_party/WebKit/Source/core/style/ScrollSnap.h
[modify] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/platform/BUILD.gn
[add] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/platform/scroll/ScrollSnapData.cpp
[add] https://crrev.com/db77c44916a84b82327d64608bfb8ef2dc4ff090/third_party/WebKit/Source/platform/scroll/ScrollSnapData.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/58239cba586d911490f30d6a0bde2277f66fa1a3

commit 58239cba586d911490f30d6a0bde2277f66fa1a3
Author: Sandra Sun <sunyunjia@chromium.org>
Date: Sat Dec 09 00:09:29 2017

Use PaddingBoxRectSize for scrollport instead of OffsetSize

This patch uses PaddingBoxRectSize as the size of the scrollport.
Compared to the OffsetWidth and OffsetHeight, this excludes scrollbar
when aligning the snap areas. It matches the spec and ensures the
accuracy for all alignments.

Bug:  778257 
Change-Id: Icca0fd0852723b443d3d5fffae9b91b81761d7f8
Reviewed-on: https://chromium-review.googlesource.com/814577
Reviewed-by: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: Majid Valipour <majidvp@chromium.org>
Commit-Queue: Sandra Sun <sunyunjia@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522930}
[modify] https://crrev.com/58239cba586d911490f30d6a0bde2277f66fa1a3/third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.cpp
[modify] https://crrev.com/58239cba586d911490f30d6a0bde2277f66fa1a3/third_party/WebKit/Source/core/page/scrolling/SnapCoordinatorTest.cpp

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/079833f209972b4b32fdd725f01f0bfbbd237a59

commit 079833f209972b4b32fdd725f01f0bfbbd237a59
Author: Sandra Sun <sunyunjia@chromium.org>
Date: Tue Dec 12 15:59:25 2017

Update CSS for scroll-snap-margin to reject percentage.

According to the spec,
https://www.w3.org/TR/css-scroll-snap-1/#propdef-scroll-snap-margin
scroll-snap-margin should only accept length value, so we reject
percentage value at parsing stage. As the percentage is no longer
needed, we also change its type to float from Length.

This patch also makes sure that all scroll-snap-margin properties
accept negative values, and adds tests for parsing scroll-snap-type,
scroll-padding and scroll-snap-margin.

Bug:  778257 
Change-Id: I6a5c7c4e76d53439af3d2976d04f47c8aafa1662
Reviewed-on: https://chromium-review.googlesource.com/782742
Reviewed-by: Darren Shen <shend@chromium.org>
Reviewed-by: Dave Tapuska <dtapuska@chromium.org>
Commit-Queue: Sandra Sun <sunyunjia@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523437}
[add] https://crrev.com/079833f209972b4b32fdd725f01f0bfbbd237a59/third_party/WebKit/LayoutTests/css-parser/snap-points-parsing.html
[modify] https://crrev.com/079833f209972b4b32fdd725f01f0bfbbd237a59/third_party/WebKit/Source/core/css/CSSProperties.json5
[modify] https://crrev.com/079833f209972b4b32fdd725f01f0bfbbd237a59/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
[modify] https://crrev.com/079833f209972b4b32fdd725f01f0bfbbd237a59/third_party/WebKit/Source/core/css/properties/longhands/ScrollSnapMarginBlockEnd.cpp
[modify] https://crrev.com/079833f209972b4b32fdd725f01f0bfbbd237a59/third_party/WebKit/Source/core/css/properties/longhands/ScrollSnapMarginBlockStart.cpp
[modify] https://crrev.com/079833f209972b4b32fdd725f01f0bfbbd237a59/third_party/WebKit/Source/core/css/properties/longhands/ScrollSnapMarginInlineEnd.cpp
[modify] https://crrev.com/079833f209972b4b32fdd725f01f0bfbbd237a59/third_party/WebKit/Source/core/css/properties/longhands/ScrollSnapMarginInlineStart.cpp
[modify] https://crrev.com/079833f209972b4b32fdd725f01f0bfbbd237a59/third_party/WebKit/Source/core/css/properties/longhands/ScrollSnapMarginSide.cpp
[modify] https://crrev.com/079833f209972b4b32fdd725f01f0bfbbd237a59/third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.cpp
[modify] https://crrev.com/079833f209972b4b32fdd725f01f0bfbbd237a59/third_party/WebKit/Source/core/style/ComputedStyle.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d2474ca0421dcfc23c6ef672f1f8b83eb157f665

commit d2474ca0421dcfc23c6ef672f1f8b83eb157f665
Author: Sandra Sun <sunyunjia@chromium.org>
Date: Thu Jan 11 15:27:57 2018

Support snapping on document element.

If the currently scrolling element is document, we should use the
document's LayoutView() instead of simply using GetLayoutBox() as other
elements.

Bug:  778257 
Change-Id: Ife2f2068eccf4c0607b3f33765a49c1ee53c36a2
Reviewed-on: https://chromium-review.googlesource.com/858232
Reviewed-by: David Bokan <bokan@chromium.org>
Commit-Queue: Sandra Sun <sunyunjia@chromium.org>
Cr-Commit-Position: refs/heads/master@{#528629}
[modify] https://crrev.com/d2474ca0421dcfc23c6ef672f1f8b83eb157f665/third_party/WebKit/Source/core/input/ScrollManager.cpp
[modify] https://crrev.com/d2474ca0421dcfc23c6ef672f1f8b83eb157f665/third_party/WebKit/Source/core/input/ScrollSnapTest.cpp
[modify] https://crrev.com/d2474ca0421dcfc23c6ef672f1f8b83eb157f665/third_party/WebKit/Source/core/page/scrolling/SnapCoordinatorTest.cpp

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a9c07f2cf10f2650f6a64457cd0b000fa7a26d70

commit a9c07f2cf10f2650f6a64457cd0b000fa7a26d70
Author: Sandra Sun <sunyunjia@chromium.org>
Date: Wed Jan 17 19:32:24 2018

Calculate snap positions based on container's border box.

As the snap_area's rect is calculated based on its container's border
box, the snap_container's rect should use PaddingBox() directly, which
is based on its border box's coordinate as well. Previously we only use
the size of PaddingBox() but ignore its location.

This patch fixes the coordinate mismatch when the container has
non-zero border width. More complicated test cases with CSS Box Mode
are added.

Bug:  778257 
Change-Id: I8f99d2a0ea8197ce5c3721c5380b7f00054aaf43
Reviewed-on: https://chromium-review.googlesource.com/868776
Reviewed-by: David Bokan <bokan@chromium.org>
Commit-Queue: Sandra Sun <sunyunjia@chromium.org>
Cr-Commit-Position: refs/heads/master@{#529851}
[modify] https://crrev.com/a9c07f2cf10f2650f6a64457cd0b000fa7a26d70/third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.cpp
[modify] https://crrev.com/a9c07f2cf10f2650f6a64457cd0b000fa7a26d70/third_party/WebKit/Source/core/page/scrolling/SnapCoordinatorTest.cpp

I believe this is now working as expected on both main and impl thread.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/32dd13568781a882fb6730f578023d3bf8f294f1

commit 32dd13568781a882fb6730f578023d3bf8f294f1
Author: Sandra Sun <sunyunjia@chromium.org>
Date: Wed Mar 14 17:14:43 2018

Snap Point selection should satisfy visibility requirement.

According to spec, https://www.w3.org/TR/css-scroll-snap-1/#snap-scope
we should only consider the snap points of visible snap areas.
This patch implements the visibility requirement by adding a field of
visible region for each snap point. It also handles the case of
visibility conflict when snapping to two axes individually.

Bug:  778257 
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel
Change-Id: I7a3d2aa6b9c1293df3f05118152f105fa3265d29
Reviewed-on: https://chromium-review.googlesource.com/814874
Commit-Queue: Sandra Sun <sunyunjia@chromium.org>
Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Reviewed-by: Ali Juma <ajuma@chromium.org>
Reviewed-by: Majid Valipour <majidvp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543111}
[modify] https://crrev.com/32dd13568781a882fb6730f578023d3bf8f294f1/cc/input/scroll_snap_data.cc
[modify] https://crrev.com/32dd13568781a882fb6730f578023d3bf8f294f1/cc/input/scroll_snap_data.h
[modify] https://crrev.com/32dd13568781a882fb6730f578023d3bf8f294f1/cc/input/scroll_snap_data_unittest.cc
[modify] https://crrev.com/32dd13568781a882fb6730f578023d3bf8f294f1/cc/trees/layer_tree_host_impl_unittest.cc
[add] https://crrev.com/32dd13568781a882fb6730f578023d3bf8f294f1/third_party/WebKit/LayoutTests/external/wpt/css/css-scroll-snap/snap-to-visible-areas.html
[modify] https://crrev.com/32dd13568781a882fb6730f578023d3bf8f294f1/third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.cpp
[modify] https://crrev.com/32dd13568781a882fb6730f578023d3bf8f294f1/third_party/WebKit/Source/core/page/scrolling/SnapCoordinatorTest.cpp
[modify] https://crrev.com/32dd13568781a882fb6730f578023d3bf8f294f1/third_party/WebKit/Source/platform/scroll/ScrollSnapData.h