Use VisibleSelection::InDOMTree::equalSelections() instead of operator==()

Use VisibleSelection::InDOMTree::equalSelections() instead of operator==()

This patch replaces |operator==| of |VisibleSelection| to |VisibleSelection::InDOMTree::equalSelections()|
to make meaning of code clearly, since |VisibleSelection| is defined on both
on a DOM tree and a composed tree for improving readability in code health.

BUG=n/a
TEST=no behavior changes

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=197712

[yosin_UTC9, 2015-06-24 05:34:20]

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

[yosin_UTC9, 2015-06-24 05:35:14]

PTAL

[hajimehoshi, 2015-06-24 06:48:46]

https://codereview.chromium.org/1201423002/diff/20001/Source/core/editing/Vis...
File Source/core/editing/VisibleSelection.cpp (right):

https://codereview.chromium.org/1201423002/diff/20001/Source/core/editing/Vis...
Source/core/editing/VisibleSelection.cpp:1158: if (selection1.affinity() !=
selection2.affinity() || selection1.isDirectional() !=
selection2.isDirectional())
Why is this needed? This seems redundant. The composed tree version doesn't have
this.

https://codereview.chromium.org/1201423002/diff/20001/Source/core/editing/Vis...
Source/core/editing/VisibleSelection.cpp:1161: if (selection1.isNone())
This could also be redundant, but I'm not sure. What do you think?

[yosin_UTC9, 2015-06-24 07:02:52]

https://codereview.chromium.org/1201423002/diff/20001/Source/core/editing/Vis...
File Source/core/editing/VisibleSelection.cpp (right):

https://codereview.chromium.org/1201423002/diff/20001/Source/core/editing/Vis...
Source/core/editing/VisibleSelection.cpp:1158: if (selection1.affinity() !=
selection2.affinity() || selection1.isDirectional() !=
selection2.isDirectional())
On 2015/06/24 06:48:45, hajimehoshi wrote:
> Why is this needed? This seems redundant. The composed tree version doesn't
have
> this.

I just copied from original code.

It seems we need to have this. :-<

Below link describes the reason of this code:
https://codereview.chromium.org/1089283002#msg14

https://codereview.chromium.org/1201423002/diff/20001/Source/core/editing/Vis...
Source/core/editing/VisibleSelection.cpp:1161: if (selection1.isNone())
On 2015/06/24 06:48:45, hajimehoshi wrote:
> This could also be redundant, but I'm not sure. What do you think?

I just copied from original code.
If we should remove them, we should have another patch.

This code avoids to call |Position::operator==()| on null case.

[hajimehoshi, 2015-06-24 07:04:53]

lgtm

[hajimehoshi, 2015-06-24 07:05:07]

The CQ bit was checked by hajimehoshi@chromium.org

[commit-bot: I haz the power, 2015-06-24 07:05:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1201423002/20001

[commit-bot: I haz the power, 2015-06-24 07:57:57]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=197712