Change requiresLineBox to return false for empty-text inline.

Change requiresLineBox to return false for empty-text inline.

.:: WHAT ::.
This patch fixes trailing whitespace problem with empty ::pseudo.content in Inline Layout flow.
Example:
<style>
  .pseudo::before {
     content:'';
  }
</style>

<div class="pseudo">
<img/></div>

Layout Tree:
...
      LayoutBlockFlow {DIV} at (0,0) size 784x20
        LayoutInline {<pseudo:before>} at (0,0) size 0x0
          LayoutTextFragment (anonymous) at (0,0) size 0x0
        LayoutText {#text} at (0,0) size 4x19
          text run at (0,0) width 4: " "         <- trailing whitespace
        LayoutImage {IMG} at (4,15) size 0x
...

.:: WHY ::.
The root cause of the issue is that the empty LayoutTextFragement(::pseudo.content) is recognized as requiresLineBox during the inline-walk. As a result LineBreaker::nextLineBreak handles LayoutTextFragement(::pseudo.content) as a line break and lays out the following real line break "\n" as an independent LayoutText element.

.:: HOW ::.
To fix the issue requiresLineBox was changed to return false if the current LineLayoutItem is Text and empty. This is similar to what we do for inline boxes with collapsible whitespaces.

.:: Rebasline ::.
2 tests need to be rebaseline because their test expectation includes a trailing whitespace
- third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content-expected.html
- third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content.html

BUG=445243
TEST=third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content.html

Committed: https://crrev.com/09cfb18fdabab040b47b637331ed5e2bd4d8a7ad
Cr-Commit-Position: refs/heads/master@{#409438}

[Gleb Lanbin, 2016-08-01 21:41:18]

Patchset #1 (id:1) has been deleted

[Gleb Lanbin, 2016-08-01 21:44:01]

Description was changed from

==========
Make ContentData->LayoutTextFragment to be a non-skippable(non-empty) inline.

BUG=445243
==========

to

==========
Make ContentData->LayoutTextFragment to be a non-skippable(non-empty) inline.

This patch adds a whitespace placeholder
ContentData->LayoutTextFragment(::pseudo.content) if it's empty. This is needed
so LayoutTextFragment will not be skipped during the layout time.

LayoutBlockFlowLine's InlineIterator skips all empty inlines and mistakenly
recognizes "\n" as a next non empty layout object.

All trailing whitespaces will be removed during the layout, so LayoutTree
remains unchanged.

See http://crrev.com/825163005/#msg8 for more detailed explanation.

BUG=445243
TEST=third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content.html
==========

[Gleb Lanbin, 2016-08-01 21:44:28]

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

[Gleb Lanbin, 2016-08-01 21:44:44]

glebl@chromium.org changed reviewers:
+ eae@chromium.org

[commit-bot: I haz the power, 2016-08-01 21:44:58]

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, 2016-08-01 23:27:32]

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

[commit-bot: I haz the power, 2016-08-01 23:27:33]

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_...)

[Gleb Lanbin, 2016-08-02 18:54:49]

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

[commit-bot: I haz the power, 2016-08-02 18:55:47]

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

[Gleb Lanbin, 2016-08-02 19:16:48]

Description was changed from

==========
Make ContentData->LayoutTextFragment to be a non-skippable(non-empty) inline.

This patch adds a whitespace placeholder
ContentData->LayoutTextFragment(::pseudo.content) if it's empty. This is needed
so LayoutTextFragment will not be skipped during the layout time.

LayoutBlockFlowLine's InlineIterator skips all empty inlines and mistakenly
recognizes "\n" as a next non empty layout object.

All trailing whitespaces will be removed during the layout, so LayoutTree
remains unchanged.

See http://crrev.com/825163005/#msg8 for more detailed explanation.

BUG=445243
TEST=third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content.html
==========

to

==========
Change requiresLineBox to return false for empty-text inline.

.:: WHAT ::.
This patch fixes trailing whitespace problem with empty ::pseudo.content in
Inline Layout flow.
Example:
<style>
  .pseudo::before {
     content:'';
  }
</style>
 
<div class="pseudo">
<img/></div>

Layout Tree:
...
      LayoutBlockFlow {DIV} at (0,0) size 784x20
        LayoutInline {<pseudo:before>} at (0,0) size 0x0
          LayoutTextFragment (anonymous) at (0,0) size 0x0
        LayoutText {#text} at (0,0) size 4x19
          text run at (0,0) width 4: " "         <- trailing whitespace
        LayoutImage {IMG} at (4,15) size 0x
...

.:: WHY ::.
The root cause of the issue is that the empty
LayoutTextFragement(::pseudo.content) is recognized as requiresLineBox during
the inline-walk. As a result LineBreaker::nextLineBreak handles
LayoutTextFragement(::pseudo.content) as a line break and lays out the following
real line break "\n" as an independent LayoutText element.

.:: HOW ::.
To fix the issue requiresLineBox was changed to return false if the current
LineLayoutItem is Text and empty. This is similar to what we do for inline boxes
with collapsible whitespaces.

.:: Rebasline ::.
2 tests need to be rebaseline because their test expectation includes a trailing
whitespace
-
third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content-expected.html
-
third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content.html

BUG=445243
TEST=third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content.html
==========

[commit-bot: I haz the power, 2016-08-02 20:40:53]

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

[commit-bot: I haz the power, 2016-08-02 20:40:54]

Dry run: This issue passed the CQ dry run.

[eae, 2016-08-02 20:52:04]

LGTM

https://codereview.chromium.org/2204593003/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/line/BreakingContextInlineHeaders.h
(right):

https://codereview.chromium.org/2204593003/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/line/BreakingContextInlineHeaders.h:209:
if (it.getLineLayoutItem().isEmptyText()) {
NIT: No curly brackets around one-line control-flow statements (see the
conditions below).

[Gleb Lanbin, 2016-08-02 23:17:55]

thanks for the review

https://codereview.chromium.org/2204593003/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/line/BreakingContextInlineHeaders.h
(right):

https://codereview.chromium.org/2204593003/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/line/BreakingContextInlineHeaders.h:209:
if (it.getLineLayoutItem().isEmptyText()) {
On 2016/08/02 20:52:04, eae wrote:
> NIT: No curly brackets around one-line control-flow statements (see the
> conditions below).

Done.

[Gleb Lanbin, 2016-08-02 23:18:04]

The CQ bit was checked by glebl@chromium.org

[Gleb Lanbin, 2016-08-02 23:18:04]

The patchset sent to the CQ was uploaded after l-g-t-m from eae@chromium.org
Link to the patchset: https://codereview.chromium.org/2204593003/#ps60001
(title: "remove curly brackets around one-line control-flow statements")

[commit-bot: I haz the power, 2016-08-02 23:18:57]

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, 2016-08-03 02:33:50]

Description was changed from

==========
Change requiresLineBox to return false for empty-text inline.

.:: WHAT ::.
This patch fixes trailing whitespace problem with empty ::pseudo.content in
Inline Layout flow.
Example:
<style>
  .pseudo::before {
     content:'';
  }
</style>
 
<div class="pseudo">
<img/></div>

Layout Tree:
...
      LayoutBlockFlow {DIV} at (0,0) size 784x20
        LayoutInline {<pseudo:before>} at (0,0) size 0x0
          LayoutTextFragment (anonymous) at (0,0) size 0x0
        LayoutText {#text} at (0,0) size 4x19
          text run at (0,0) width 4: " "         <- trailing whitespace
        LayoutImage {IMG} at (4,15) size 0x
...

.:: WHY ::.
The root cause of the issue is that the empty
LayoutTextFragement(::pseudo.content) is recognized as requiresLineBox during
the inline-walk. As a result LineBreaker::nextLineBreak handles
LayoutTextFragement(::pseudo.content) as a line break and lays out the following
real line break "\n" as an independent LayoutText element.

.:: HOW ::.
To fix the issue requiresLineBox was changed to return false if the current
LineLayoutItem is Text and empty. This is similar to what we do for inline boxes
with collapsible whitespaces.

.:: Rebasline ::.
2 tests need to be rebaseline because their test expectation includes a trailing
whitespace
-
third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content-expected.html
-
third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content.html

BUG=445243
TEST=third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content.html
==========

to

==========
Change requiresLineBox to return false for empty-text inline.

.:: WHAT ::.
This patch fixes trailing whitespace problem with empty ::pseudo.content in
Inline Layout flow.
Example:
<style>
  .pseudo::before {
     content:'';
  }
</style>
 
<div class="pseudo">
<img/></div>

Layout Tree:
...
      LayoutBlockFlow {DIV} at (0,0) size 784x20
        LayoutInline {<pseudo:before>} at (0,0) size 0x0
          LayoutTextFragment (anonymous) at (0,0) size 0x0
        LayoutText {#text} at (0,0) size 4x19
          text run at (0,0) width 4: " "         <- trailing whitespace
        LayoutImage {IMG} at (4,15) size 0x
...

.:: WHY ::.
The root cause of the issue is that the empty
LayoutTextFragement(::pseudo.content) is recognized as requiresLineBox during
the inline-walk. As a result LineBreaker::nextLineBreak handles
LayoutTextFragement(::pseudo.content) as a line break and lays out the following
real line break "\n" as an independent LayoutText element.

.:: HOW ::.
To fix the issue requiresLineBox was changed to return false if the current
LineLayoutItem is Text and empty. This is similar to what we do for inline boxes
with collapsible whitespaces.

.:: Rebasline ::.
2 tests need to be rebaseline because their test expectation includes a trailing
whitespace
-
third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content-expected.html
-
third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content.html

BUG=445243
TEST=third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content.html
==========

[commit-bot: I haz the power, 2016-08-03 02:33:51]

Committed patchset #3 (id:60001)

[commit-bot: I haz the power, 2016-08-03 02:36:21]

Description was changed from

==========
Change requiresLineBox to return false for empty-text inline.

.:: WHAT ::.
This patch fixes trailing whitespace problem with empty ::pseudo.content in
Inline Layout flow.
Example:
<style>
  .pseudo::before {
     content:'';
  }
</style>
 
<div class="pseudo">
<img/></div>

Layout Tree:
...
      LayoutBlockFlow {DIV} at (0,0) size 784x20
        LayoutInline {<pseudo:before>} at (0,0) size 0x0
          LayoutTextFragment (anonymous) at (0,0) size 0x0
        LayoutText {#text} at (0,0) size 4x19
          text run at (0,0) width 4: " "         <- trailing whitespace
        LayoutImage {IMG} at (4,15) size 0x
...

.:: WHY ::.
The root cause of the issue is that the empty
LayoutTextFragement(::pseudo.content) is recognized as requiresLineBox during
the inline-walk. As a result LineBreaker::nextLineBreak handles
LayoutTextFragement(::pseudo.content) as a line break and lays out the following
real line break "\n" as an independent LayoutText element.

.:: HOW ::.
To fix the issue requiresLineBox was changed to return false if the current
LineLayoutItem is Text and empty. This is similar to what we do for inline boxes
with collapsible whitespaces.

.:: Rebasline ::.
2 tests need to be rebaseline because their test expectation includes a trailing
whitespace
-
third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content-expected.html
-
third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content.html

BUG=445243
TEST=third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content.html
==========

to

==========
Change requiresLineBox to return false for empty-text inline.

.:: WHAT ::.
This patch fixes trailing whitespace problem with empty ::pseudo.content in
Inline Layout flow.
Example:
<style>
  .pseudo::before {
     content:'';
  }
</style>

<div class="pseudo">
<img/></div>

Layout Tree:
...
      LayoutBlockFlow {DIV} at (0,0) size 784x20
        LayoutInline {<pseudo:before>} at (0,0) size 0x0
          LayoutTextFragment (anonymous) at (0,0) size 0x0
        LayoutText {#text} at (0,0) size 4x19
          text run at (0,0) width 4: " "         <- trailing whitespace
        LayoutImage {IMG} at (4,15) size 0x
...

.:: WHY ::.
The root cause of the issue is that the empty
LayoutTextFragement(::pseudo.content) is recognized as requiresLineBox during
the inline-walk. As a result LineBreaker::nextLineBreak handles
LayoutTextFragement(::pseudo.content) as a line break and lays out the following
real line break "\n" as an independent LayoutText element.

.:: HOW ::.
To fix the issue requiresLineBox was changed to return false if the current
LineLayoutItem is Text and empty. This is similar to what we do for inline boxes
with collapsible whitespaces.

.:: Rebasline ::.
2 tests need to be rebaseline because their test expectation includes a trailing
whitespace
-
third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content-expected.html
-
third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content.html

BUG=445243
TEST=third_party/WebKit/LayoutTests/fast/css-generated-content/pseudo-inline-with-empty-content.html

Committed: https://crrev.com/09cfb18fdabab040b47b637331ed5e2bd4d8a7ad
Cr-Commit-Position: refs/heads/master@{#409438}
==========

[commit-bot: I haz the power, 2016-08-03 02:36:23]

Patchset 3 (id:??) landed as
https://crrev.com/09cfb18fdabab040b47b637331ed5e2bd4d8a7ad
Cr-Commit-Position: refs/heads/master@{#409438}