Make VisiblePosition::init to not use being constructed object

Make VisiblePosition::init not to use being constructed object

Before this patch, |VisiblePosition::init()|, which is called by constructor,
used constructing object with |inSameLine()|. This pattern prevents us to
make |VisiblePostion| to work with composed tree.

This patch mitigates this issue by making |inSameLine()| and functions used
by |inSameLine| to take |PositionWithAffinity| instead of |VisiblePosition|.

Since |VisiblePosition::init()| calls |inSameLine()| with |this| pointer, all
functions called |inSameLine()| can't uses |VisiblePosition|. This is reason
why this patch changes following functions at once:
 - inSameLine
 - honorEditingBoundaryAtOrBeforeOf
 - startOfLine

This patch is result of collaboration work with hajimehoshi@chromium.org
for selection of web components. After this patch, we are going to
implement another strategies for the composed tree. We've already
prepared that at http://crrev.com/1106433002.

BUG=275851
TEST=n/a; No behavior changes.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=197558

[yosin_UTC9, 2015-06-19 08:38:11]

yosin@chromium.org changed reviewers:
+ tkent@chromium.org

[yosin_UTC9, 2015-06-19 09:06:53]

PTAL

[yosin_UTC9, 2015-06-19 11:52:14]

Looking for layout test failure... :-<

[yosin_UTC9, 2015-06-22 04:38:07]

yosin@chromium.org changed reviewers:
- tkent@chromium.org

[yosin_UTC9, 2015-06-22 06:11:07]

yosin@chromium.org changed reviewers:
+ tkent@chromium.org

[yosin_UTC9, 2015-06-22 06:11:07]

PTAL

[tkent, 2015-06-22 06:24:55]

https://codereview.chromium.org/1191283002/diff/40001/Source/core/editing/Pos...
File Source/core/editing/PositionWithAffinity.cpp (right):

https://codereview.chromium.org/1191283002/diff/40001/Source/core/editing/Pos...
Source/core/editing/PositionWithAffinity.cpp:31: return m_affinity ==
other.m_affinity && m_position == other.m_position;
So, an object with m_affinity:UPSTREAM and m_position:null and another object
with m_affinity:DOWNSTREAM and m_position:null are not equal.  Is it an expected
behavior?

[yosin_UTC9, 2015-06-22 06:55:08]

PTAL

https://codereview.chromium.org/1191283002/diff/40001/Source/core/editing/Pos...
File Source/core/editing/PositionWithAffinity.cpp (right):

https://codereview.chromium.org/1191283002/diff/40001/Source/core/editing/Pos...
Source/core/editing/PositionWithAffinity.cpp:31: return m_affinity ==
other.m_affinity && m_position == other.m_position;
On 2015/06/22 06:24:55, tkent wrote:
> So, an object with m_affinity:UPSTREAM and m_position:null and another object
> with m_affinity:DOWNSTREAM and m_position:null are not equal.  Is it an
expected
> behavior?

Good catch!
Done.

[tkent, 2015-06-22 07:04:59]

lgtm

https://codereview.chromium.org/1191283002/diff/60001/Source/core/editing/Pos...
File Source/core/editing/PositionWithAffinity.cpp (right):

https://codereview.chromium.org/1191283002/diff/60001/Source/core/editing/Pos...
Source/core/editing/PositionWithAffinity.cpp:31: if (isNull())
Please document this in PositionWithAffinity.h.

[yosin_UTC9, 2015-06-22 07:25:35]

Thanks!

Committing...

https://codereview.chromium.org/1191283002/diff/60001/Source/core/editing/Pos...
File Source/core/editing/PositionWithAffinity.cpp (right):

https://codereview.chromium.org/1191283002/diff/60001/Source/core/editing/Pos...
Source/core/editing/PositionWithAffinity.cpp:31: if (isNull())
On 2015/06/22 07:04:59, tkent wrote:
> Please document this in PositionWithAffinity.h.

Done.

[yosin_UTC9, 2015-06-22 07:25:40]

The CQ bit was checked by yosin@chromium.org

[yosin_UTC9, 2015-06-22 07:25:41]

The patchset sent to the CQ was uploaded after l-g-t-m from tkent@chromium.org
Link to the patchset: https://codereview.chromium.org/1191283002/#ps80001
(title: "2015-06-22T16:23:26　Add a comment to
PositionWIthAffinity::operator==()")

[commit-bot: I haz the power, 2015-06-22 07:25:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1191283002/80001

[commit-bot: I haz the power, 2015-06-22 08:44:02]

Committed patchset #5 (id:80001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=197558