Convert main-thread overscroll parameters into viewport space.

Convert main-thread overscroll parameters into viewport space.

The overscroll functions in the Browser expect these values to be in the
viewport coordinate space. i.e. If the page is scaled by a factor of 2,
if the user moves their finger by 10px and all of it is consumed by overscroll,
the overscroll method should get back a delta of 10px, even though we tried
scrolling the root frame by 5px.

More generally, coordinates coming out of Blink should almost always be in
viewport/renderer/widget coordinates since it's most useful in the renderer and
it's difficult for client code to compensate for the visual viewport transform
since that's an internal implementation detail of Blink (mostly).

Also cleaned up the naming of these parameters through the call chain.

BUG=602476
Committed: https://crrev.com/e53a10f9b029bf4367567a170fc77d6d6d42fe91
Cr-Commit-Position: refs/heads/master@{#387154}

[bokan, 2016-04-12 18:46:42]

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

[bokan, 2016-04-12 18:46:55]

Description was changed from

==========
Convert main-thread overscroll parameters into viewport space.

The overscroll functions in the Browser expect these values to be in the
viewport coordinate space. i.e. If the page is scaled by a factor of 2,
if the user moves their finger by 10px and all of it is consumed by overscroll,
the overscroll method should get back a delta of 10px, even though we tried
scrolling the root frame by 5px.

More generally, coordinates coming out of Blink should almost always be in
viewport/renderer/widget coordinates since it's most useful in the renderer and
it's difficult for client code to compensate for the visual viewport transform
since that's an internal implementation detail of Blink (mostly).

Also cleaned up the naming of these parameters through the call chain.

BUG=602476
==========

to

==========
Convert main-thread overscroll parameters into viewport space.

The overscroll functions in the Browser expect these values to be in the
viewport coordinate space. i.e. If the page is scaled by a factor of 2,
if the user moves their finger by 10px and all of it is consumed by overscroll,
the overscroll method should get back a delta of 10px, even though we tried
scrolling the root frame by 5px.

More generally, coordinates coming out of Blink should almost always be in
viewport/renderer/widget coordinates since it's most useful in the renderer and
it's difficult for client code to compensate for the visual viewport transform
since that's an internal implementation detail of Blink (mostly).

Also cleaned up the naming of these parameters through the call chain.

BUG=602476
==========

[bokan, 2016-04-12 18:46:55]

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

[commit-bot: I haz the power, 2016-04-12 18:47:00]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1879103002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1879103002/1

[bokan, 2016-04-12 18:47:44]

+Majid, since I think you and I originally reviewed these patches.

[commit-bot: I haz the power, 2016-04-12 18:55:03]

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

[commit-bot: I haz the power, 2016-04-12 18:55:04]

Dry run: Try jobs failed on following builders:
  cast_shell_android on tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/cast_shell_a...)

[bokan, 2016-04-13 17:26:34]

gentle ping :)

[majidvp, 2016-04-13 18:20:38]

lgtm with nits

https://codereview.chromium.org/1879103002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/input/EventHandler.cpp (right):

https://codereview.chromium.org/1879103002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/input/EventHandler.cpp:2376: void
EventHandler::handleOverscroll(const ScrollResult& scrollResult, const
FloatPoint& positionInRootFrame, const FloatSize& velocity)
s/velocity/velocityInRootFram/

https://codereview.chromium.org/1879103002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/input/EventHandler.cpp:2386: // to go back to
viewport space.
Can we simplify this comment by referencing from->to coordinate spaces e.g., 

translate  delta, position and velocity of the incoming event from root frame
coordinate space to viewport coordinate space before reporting.

[bokan, 2016-04-13 19:43:50]

https://codereview.chromium.org/1879103002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/input/EventHandler.cpp (right):

https://codereview.chromium.org/1879103002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/input/EventHandler.cpp:2376: void
EventHandler::handleOverscroll(const ScrollResult& scrollResult, const
FloatPoint& positionInRootFrame, const FloatSize& velocity)
On 2016/04/13 18:20:38, majidvp wrote:
> s/velocity/velocityInRootFram/

Done.

https://codereview.chromium.org/1879103002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/input/EventHandler.cpp:2386: // to go back to
viewport space.
On 2016/04/13 18:20:38, majidvp wrote:
> Can we simplify this comment by referencing from->to coordinate spaces e.g., 
> 
> translate  delta, position and velocity of the incoming event from root frame
> coordinate space to viewport coordinate space before reporting.

Looking at this again, this comment isn't adding much, it's clear we're going
from root frame->viewport by looking at the code so I've removed the comment.
Let me know if you disagree.

[bokan, 2016-04-13 19:45:01]

bokan@chromium.org changed reviewers:
+ nasko@chromium.org, rbyers@chromium.org

[bokan, 2016-04-13 19:45:01]

+nasko@ for content/
+rbyers@ for WebKit/public

[bokan, 2016-04-13 20:06:46]

bokan@chromium.org changed reviewers:
- nasko@chromium.org

[bokan, 2016-04-13 20:08:06]

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

[bokan, 2016-04-13 20:08:20]

-nasko@/+nick@ for content/

[Rick Byers, 2016-04-13 20:46:49]

public LGTM

[ncarter (slow), 2016-04-13 22:15:31]

content lgtm

[bokan, 2016-04-13 22:22:24]

The CQ bit was checked by bokan@chromium.org

[bokan, 2016-04-13 22:22:24]

The patchset sent to the CQ was uploaded after l-g-t-m from majidvp@chromium.org
Link to the patchset: https://codereview.chromium.org/1879103002/#ps20001
(title: "Majid's review")

[commit-bot: I haz the power, 2016-04-13 22:22:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1879103002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1879103002/20001

[commit-bot: I haz the power, 2016-04-13 23:48:42]

Description was changed from

==========
Convert main-thread overscroll parameters into viewport space.

The overscroll functions in the Browser expect these values to be in the
viewport coordinate space. i.e. If the page is scaled by a factor of 2,
if the user moves their finger by 10px and all of it is consumed by overscroll,
the overscroll method should get back a delta of 10px, even though we tried
scrolling the root frame by 5px.

More generally, coordinates coming out of Blink should almost always be in
viewport/renderer/widget coordinates since it's most useful in the renderer and
it's difficult for client code to compensate for the visual viewport transform
since that's an internal implementation detail of Blink (mostly).

Also cleaned up the naming of these parameters through the call chain.

BUG=602476
==========

to

==========
Convert main-thread overscroll parameters into viewport space.

The overscroll functions in the Browser expect these values to be in the
viewport coordinate space. i.e. If the page is scaled by a factor of 2,
if the user moves their finger by 10px and all of it is consumed by overscroll,
the overscroll method should get back a delta of 10px, even though we tried
scrolling the root frame by 5px.

More generally, coordinates coming out of Blink should almost always be in
viewport/renderer/widget coordinates since it's most useful in the renderer and
it's difficult for client code to compensate for the visual viewport transform
since that's an internal implementation detail of Blink (mostly).

Also cleaned up the naming of these parameters through the call chain.

BUG=602476
==========

[commit-bot: I haz the power, 2016-04-13 23:48:44]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-04-13 23:49:41]

Description was changed from

==========
Convert main-thread overscroll parameters into viewport space.

The overscroll functions in the Browser expect these values to be in the
viewport coordinate space. i.e. If the page is scaled by a factor of 2,
if the user moves their finger by 10px and all of it is consumed by overscroll,
the overscroll method should get back a delta of 10px, even though we tried
scrolling the root frame by 5px.

More generally, coordinates coming out of Blink should almost always be in
viewport/renderer/widget coordinates since it's most useful in the renderer and
it's difficult for client code to compensate for the visual viewport transform
since that's an internal implementation detail of Blink (mostly).

Also cleaned up the naming of these parameters through the call chain.

BUG=602476
==========

to

==========
Convert main-thread overscroll parameters into viewport space.

The overscroll functions in the Browser expect these values to be in the
viewport coordinate space. i.e. If the page is scaled by a factor of 2,
if the user moves their finger by 10px and all of it is consumed by overscroll,
the overscroll method should get back a delta of 10px, even though we tried
scrolling the root frame by 5px.

More generally, coordinates coming out of Blink should almost always be in
viewport/renderer/widget coordinates since it's most useful in the renderer and
it's difficult for client code to compensate for the visual viewport transform
since that's an internal implementation detail of Blink (mostly).

Also cleaned up the naming of these parameters through the call chain.

BUG=602476

Committed: https://crrev.com/e53a10f9b029bf4367567a170fc77d6d6d42fe91
Cr-Commit-Position: refs/heads/master@{#387154}
==========

[commit-bot: I haz the power, 2016-04-13 23:49:43]

Patchset 2 (id:??) landed as
https://crrev.com/e53a10f9b029bf4367567a170fc77d6d6d42fe91
Cr-Commit-Position: refs/heads/master@{#387154}