Add full offset mapping construction in a block

Add full offset mapping construction in a block

This CL constructs the DOM-to-TextContent offset mapping of a block. It adds
the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_result.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

Note 1: The patch can be made cleaner if we do not write whitespace-collapsed
strings back to LayoutText after layout.

Note 2: The built offset mapping is wrong when text-transform expands/removes
characters (e.g., ß => SS)

BUG=699017
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng

Review-Url: https://codereview.chromium.org/2963093002
Cr-Commit-Position: refs/heads/master@{#487489}
Committed: https://chromium.googlesource.com/chromium/src/+/13b1999a87a545bcab93d66a2294758c3125a84b

[Xiaocheng, 2017-06-29 02:32:42]

Description was changed from

==========
WIP Full offset mapping construction prototype

BUG=
==========

to

==========
WIP Full offset mapping construction prototype

BUG=
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

[Xiaocheng, 2017-06-29 21:49:05]

Description was changed from

==========
WIP Full offset mapping construction prototype

BUG=
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

to

==========
DO-NOT-COMMIT Full offset mapping construction prototype

This is an all-in-one CL constructing the DOM-to-TextContent offset mapping of
a LayoutNGBlockFlow. It adds the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_builder.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

BUG=
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

[Xiaocheng, 2017-06-29 21:50:35]

Description was changed from

==========
DO-NOT-COMMIT Full offset mapping construction prototype

This is an all-in-one CL constructing the DOM-to-TextContent offset mapping of
a LayoutNGBlockFlow. It adds the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_builder.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

BUG=
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

to

==========
DO-NOT-COMMIT Full offset mapping construction prototype

This is an all-in-one CL constructing the DOM-to-TextContent offset mapping of
a LayoutNGBlockFlow. It adds the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_builder.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

Note: The patch can be made cleaner if we do not write whitespace-collapsed
strings back to LayoutText after layout.

BUG=
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

[Xiaocheng, 2017-06-29 21:50:58]

Description was changed from

==========
DO-NOT-COMMIT Full offset mapping construction prototype

This is an all-in-one CL constructing the DOM-to-TextContent offset mapping of
a LayoutNGBlockFlow. It adds the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_builder.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

Note: The patch can be made cleaner if we do not write whitespace-collapsed
strings back to LayoutText after layout.

BUG=
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

to

==========
DO-NOT-COMMIT Full offset mapping construction prototype

This is an all-in-one CL constructing the DOM-to-TextContent offset mapping of
a LayoutNGBlockFlow. It adds the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_builder.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

Note: The patch can be made cleaner if we do not write whitespace-collapsed
strings back to LayoutText after layout.

BUG=699017
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

[Xiaocheng, 2017-06-29 21:52:54]

xiaochengh@chromium.org changed reviewers:
+ eae@chromium.org, ikilpatrick@chromium.org, kojii@chromium.org,
yoichio@chromium.org, yosin@chromium.org

[Xiaocheng, 2017-06-29 21:52:54]

I've put up an all-in-one prototype that builds the offset mapping of a
LayoutNGBlockFlow.

Please let me know if you have any thoughts. Thanks!

[Xiaocheng, 2017-06-29 21:54:41]

Description was changed from

==========
DO-NOT-COMMIT Full offset mapping construction prototype

This is an all-in-one CL constructing the DOM-to-TextContent offset mapping of
a LayoutNGBlockFlow. It adds the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_builder.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

Note: The patch can be made cleaner if we do not write whitespace-collapsed
strings back to LayoutText after layout.

BUG=699017
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

to

==========
DO-NOT-COMMIT Full offset mapping construction prototype

This is an all-in-one CL constructing the DOM-to-TextContent offset mapping of
a LayoutNGBlockFlow. It adds the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_builder.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

Note 1: The patch can be made cleaner if we do not write whitespace-collapsed
strings back to LayoutText after layout.

Note 2: The built offset mapping is wrong when text-transform expands/removes
characters (e.g., ß => SS)

BUG=699017
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

[eae, 2017-06-29 22:05:48]

Overall this approach looks fine to me.

https://codereview.chromium.org/2963093002/diff/60001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc (right):

https://codereview.chromium.org/2963093002/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc:167: template
<typename OffsetMappingBuilder>
What are the templates used for here? It's not immediately obvious from reading
the code.

[Xiaocheng, 2017-06-29 22:18:38]

https://codereview.chromium.org/2963093002/diff/60001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc (right):

https://codereview.chromium.org/2963093002/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc:167: template
<typename OffsetMappingBuilder>
On 2017/06/29 at 22:05:48, eae wrote:
> What are the templates used for here? It's not immediately obvious from
reading the code.

The primary purpose is to indicate whether we are doing layout or building
offset mapping:
- When EmptyOffsetMappingBuilder is passed in: doing layout
- When NGOffsetMappingBuilder is passed in: building offset mapping

This allows code sharing when different behaviors are needed. For example, when
doing layout, we call LayoutObject::ClearNeedsLayout() after collecting an
inline. We don't do that when building offset mapping.

There is also performance considerations, since we don't need to perform
branching with templates.

[yosin_UTC9, 2017-06-30 02:03:05]

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
File
third_party/WebKit/Source/core/layout/ng/inline/empty_offset_mapping_builder.h
(right):

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/empty_offset_mapping_builder.h:28:
void Composite(const EmptyOffsetMappingBuilder&) {}
nit: Try to alphabetical order since expect for Composite(), others are
alphabetical order.

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc (right):

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc:177: String
GetTextForInlineCollection(const LayoutText& node) {
s/String/const String/

For avoiding to string copy.
Note: LayoutText::GetString() returns |const String&|.

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc:264:
Vector<NGInlineItem> items;
Could you add TODO comment for |BuildOffsetMapping()| will not collect
NGInlineItem and TextContent?
It seems that it is too early to make NGInlineItemBuilder to fully abstract
about artifacts, NGInlineItem or Offset Mapp of builder at this time.

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/ng/inline/ng_offset_mapping_builder.h
(right):

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_offset_mapping_builder.h:28:
Vector<NGOffsetMappingUnit> units;
How many elements does |units| have? Is it number of LayoutObject under the
element of LayoutNGBlockFlow?
Is this LayoutObject LayoutText only?

BTW, kojii@ doesn't want to use LayoutText under LayoutNGBlockFlow. 
Should we put a TODO that we'll use other than LayoutText?
I'm not sure about details. kojii@ may suggest something.

[yoichio, 2017-06-30 02:04:27]

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/ng/inline/ng_offset_mapping_builder.h
(right):

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_offset_mapping_builder.h:18:
struct NGOffsetMappingUnit {
Please add comment about these structs.

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_offset_mapping_builder.h:20:
const LayoutObject* owner;
Why this is not Node?

[Xiaocheng, 2017-06-30 02:49:20]

Thanks for all the comments!

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
File
third_party/WebKit/Source/core/layout/ng/inline/empty_offset_mapping_builder.h
(right):

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/empty_offset_mapping_builder.h:28:
void Composite(const EmptyOffsetMappingBuilder&) {}
On 2017/06/30 at 02:03:05, yosin_UTC9 wrote:
> nit: Try to alphabetical order since expect for Composite(), others are
alphabetical order.

Done.

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc (right):

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc:177: String
GetTextForInlineCollection(const LayoutText& node) {
On 2017/06/30 at 02:03:05, yosin_UTC9 wrote:
> s/String/const String/
> 
> For avoiding to string copy.
> Note: LayoutText::GetString() returns |const String&|.

I guess this is fine, because String is basically a ref ptr of StringImpl.

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc:264:
Vector<NGInlineItem> items;
On 2017/06/30 at 02:03:05, yosin_UTC9 wrote:
> Could you add TODO comment for |BuildOffsetMapping()| will not collect
NGInlineItem and TextContent?

Done.

> It seems that it is too early to make NGInlineItemBuilder to fully abstract
about artifacts, NGInlineItem or Offset Mapp of builder at this time.

Sorry I don't understand this comment. Could you explain?

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/ng/inline/ng_offset_mapping_builder.h
(right):

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_offset_mapping_builder.h:18:
struct NGOffsetMappingUnit {
On 2017/06/30 at 02:04:26, yoichio wrote:
> Please add comment about these structs.

Done.

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_offset_mapping_builder.h:20:
const LayoutObject* owner;
On 2017/06/30 at 02:04:26, yoichio wrote:
> Why this is not Node?

I want to ensure that units with the same owner are consecutive in |units|, so
that |NGOffsetMappingResult::ranges| makes sense.

However, there's a potential issue with :first-letter, which I haven't solved:

During inline collection, strings are collected according to their layout
objects, not nodes. So for a text node with :first-letter, its first letter and
remaining text are collected separately. The property (consecutive units for the
same owner) can be violated if other strings are collected between first letter
and remaining text.

I'm wondering if this is a possible case. For safety, I'm putting LayoutObject
here.

I've added comments about this issue.

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_offset_mapping_builder.h:28:
Vector<NGOffsetMappingUnit> units;
On 2017/06/30 at 02:03:05, yosin_UTC9 wrote:
> How many elements does |units| have? Is it number of LayoutObject under the
element of LayoutNGBlockFlow?

More than that. It's currently (# LayoutText) + (# streaks of collapsed spaces).

If we want to make the mapping work correctly text-transform, then we need (#
characters expanded/collapsed due to text-transform) extra units.

> Is this LayoutObject LayoutText only?
Yes, judging from the how CollectInlinesInternal works.

> 
> BTW, kojii@ doesn't want to use LayoutText under LayoutNGBlockFlow. 
> Should we put a TODO that we'll use other than LayoutText?
> I'm not sure about details. kojii@ may suggest something.

[yoichio, 2017-06-30 05:51:46]

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/ng/inline/ng_offset_mapping_builder.h
(right):

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_offset_mapping_builder.h:18:
struct NGOffsetMappingUnit {
On 2017/06/30 02:49:20, Xiaocheng wrote:
> On 2017/06/30 at 02:04:26, yoichio wrote:
> > Please add comment about these structs.
> 
> Done.

I mean appending comment on code like,
// NGOffsetMappingUnit is a unit which consists of...
// NGBF,, blah blah blah, ,,,
// 
Something abstract of your design doc.

[kojii, 2017-06-30 06:02:31]

Thank you for working on this, looks good to me too. Just curious, why is this
"do-not-commit..prototype"? Aren't you going to brush this up towards to landing
code?

https://codereview.chromium.org/2963093002/diff/60001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc (right):

https://codereview.chromium.org/2963093002/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc:167: template
<typename OffsetMappingBuilder>
These are good explanation probably other people want to know too. Can you move
them to comments?

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/ng/inline/ng_inline_items_builder.h
(right):

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_inline_items_builder.h:106:
OffsetMappingBuilder concatenated_mapping_builder_;
Why do we need two? And what is_appending_string_ does? Can you add comments?

[yosin_UTC9, 2017-06-30 06:51:00]

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc (right):

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc:264:
Vector<NGInlineItem> items;
On 2017/06/30 at 02:49:20, Xiaocheng wrote:
> On 2017/06/30 at 02:03:05, yosin_UTC9 wrote:
> > Could you add TODO comment for |BuildOffsetMapping()| will not collect
NGInlineItem and TextContent?
> 
> Done.
> 
> > It seems that it is too early to make NGInlineItemBuilder to fully abstract
about artifacts, NGInlineItem or Offset Mapp of builder at this time.
> 
> Sorry I don't understand this comment. Could you explain?

As you mentioned before, we don't need to produce NGInlineItem and text_content_
during offset mapping. We have them already during layout.
Editing runs after LayoutClean.

NgInlineItemBuilder is still development, we can exclude producing NGInlineItem
and text_content later. It is an optimization.

[Xiaocheng, 2017-06-30 20:57:50]

Updated with more comments added.

About DO-NOT-COMMIT: This patch is an all-in-one patch for reference. It needs
further dividing and polishing.

kojii@: Could you share some ideas/plans about removing LayoutText from NG?

https://codereview.chromium.org/2963093002/diff/60001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc (right):

https://codereview.chromium.org/2963093002/diff/60001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.cc:167: template
<typename OffsetMappingBuilder>
On 2017/06/30 at 06:02:31, kojii wrote:
> These are good explanation probably other people want to know too. Can you
move them to comments?

Good idea! Done.

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/ng/inline/ng_inline_items_builder.h
(right):

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_inline_items_builder.h:106:
OffsetMappingBuilder concatenated_mapping_builder_;
On 2017/06/30 at 06:02:31, kojii wrote:
> Why do we need two? And what is_appending_string_ does? Can you add comments?

Done.

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/ng/inline/ng_offset_mapping_builder.h
(right):

https://codereview.chromium.org/2963093002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/ng/inline/ng_offset_mapping_builder.h:18:
struct NGOffsetMappingUnit {
On 2017/06/30 at 05:51:46, yoichio wrote:
> On 2017/06/30 02:49:20, Xiaocheng wrote:
> > On 2017/06/30 at 02:04:26, yoichio wrote:
> > > Please add comment about these structs.
> > 
> > Done.
> 
> I mean appending comment on code like,
> // NGOffsetMappingUnit is a unit which consists of...
> // NGBF,, blah blah blah, ,,,
> // 
> Something abstract of your design doc.

Done.

[Xiaocheng, 2017-06-30 21:03:27]

Patchset #7 (id:120001) has been deleted

[yoichio, 2017-07-03 02:29:08]

https://codereview.chromium.org/2963093002/diff/160001/third_party/WebKit/Sou...
File third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.h (right):

https://codereview.chromium.org/2963093002/diff/160001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.h:68:
NGOffsetMappingResult BuildOffsetMapping() const;
If a NGOffsetMappingResult stores the units of a LayoutNGBlockFlow,
 why a NGInlineNode builds it?

[kojii, 2017-07-03 03:10:20]

On 2017/06/30 at 20:57:50, xiaochengh wrote:
> About DO-NOT-COMMIT: This patch is an all-in-one patch for reference. It needs
further dividing and polishing.

I'm good to land this and cleanup  later, so lgtm, but if you want to work more
before landing, that's also fine too.

> kojii@: Could you share some ideas/plans about removing LayoutText from NG?

Not really concrete plans yet, but also not really concrete plans to keep it for
a long time. Probably no changes for 3 months. Likely it'll survive 6 moths, but
as we move towards to shipping, I'm counting removing LayoutInline/LayoutText is
one big thing we can reduce memory.

[kojii, 2017-07-03 03:11:57]

BTW, FYI, if we were to apply text-transform in NG, I think it's easier to apply
after whitespace collapsing, since entire strings are already there. Please
count on that possibility.

[Xiaocheng, 2017-07-03 06:02:35]

https://codereview.chromium.org/2963093002/diff/160001/third_party/WebKit/Sou...
File third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.h (right):

https://codereview.chromium.org/2963093002/diff/160001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/layout/ng/inline/ng_inline_node.h:68:
NGOffsetMappingResult BuildOffsetMapping() const;
On 2017/07/03 at 02:29:08, yoichio wrote:
> If a NGOffsetMappingResult stores the units of a LayoutNGBlockFlow,
>  why a NGInlineNode builds it?

Because this seems the easiest way to reuse the CollectInlinesInternal function
in ng_inline_node.cc.

Note that NGInlineNode::BuildOffsetMapping() might not be the final API exposed
to non-layout components. It is more likely that we implement the four APIs
(defined in the design doc) somewhere else in layout code upon
NGInlineNode::BuildOffsetMapping().

[Xiaocheng, 2017-07-03 06:04:51]

On 2017/07/03 at 03:11:57, kojii wrote:
> BTW, FYI, if we were to apply text-transform in NG, I think it's easier to
apply after whitespace collapsing, since entire strings are already there.
Please count on that possibility.

Got it. I think the current framework to build offset mapping is flexible enough
to adapt with this change.

[yoichio, 2017-07-03 07:19:02]

lgtm for result and usage.

[Xiaocheng, 2017-07-10 07:53:57]

Description was changed from

==========
DO-NOT-COMMIT Full offset mapping construction prototype

This is an all-in-one CL constructing the DOM-to-TextContent offset mapping of
a LayoutNGBlockFlow. It adds the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_builder.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

Note 1: The patch can be made cleaner if we do not write whitespace-collapsed
strings back to LayoutText after layout.

Note 2: The built offset mapping is wrong when text-transform expands/removes
characters (e.g., ß => SS)

BUG=699017
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

to

==========
DO-NOT-COMMIT Full offset mapping construction prototype

This is an all-in-one CL constructing the DOM-to-TextContent offset mapping of
a LayoutNGBlockFlow. It adds the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_builder.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

Note 1: The patch can be made cleaner if we do not write whitespace-collapsed
strings back to LayoutText after layout.

Note 2: The built offset mapping is wrong when text-transform expands/removes
characters (e.g., ß => SS)

Remaining issues:

1. Avoid copy construction when returning result

2. Divide into sub-patches

BUG=699017
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

[Xiaocheng, 2017-07-10 07:55:26]

Description was changed from

==========
DO-NOT-COMMIT Full offset mapping construction prototype

This is an all-in-one CL constructing the DOM-to-TextContent offset mapping of
a LayoutNGBlockFlow. It adds the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_builder.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

Note 1: The patch can be made cleaner if we do not write whitespace-collapsed
strings back to LayoutText after layout.

Note 2: The built offset mapping is wrong when text-transform expands/removes
characters (e.g., ß => SS)

Remaining issues:

1. Avoid copy construction when returning result

2. Divide into sub-patches

BUG=699017
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

to

==========
DO-NOT-COMMIT Full offset mapping construction prototype

This is an all-in-one CL constructing the DOM-to-TextContent offset mapping of
a LayoutNGBlockFlow. It adds the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_builder.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

Note 1: The patch can be made cleaner if we do not write whitespace-collapsed
strings back to LayoutText after layout.

Note 2: The built offset mapping is wrong when text-transform expands/removes
characters (e.g., ß => SS)

Remaining issues:

1. Avoid copy construction when returning result

2. Move new classes to their files, and divide into sub-patches

BUG=699017
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

[Xiaocheng, 2017-07-17 21:22:48]

Description was changed from

==========
DO-NOT-COMMIT Full offset mapping construction prototype

This is an all-in-one CL constructing the DOM-to-TextContent offset mapping of
a LayoutNGBlockFlow. It adds the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_builder.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

Note 1: The patch can be made cleaner if we do not write whitespace-collapsed
strings back to LayoutText after layout.

Note 2: The built offset mapping is wrong when text-transform expands/removes
characters (e.g., ß => SS)

Remaining issues:

1. Avoid copy construction when returning result

2. Move new classes to their files, and divide into sub-patches

BUG=699017
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

to

==========
Add full offset mapping construction in a block

This CL constructs the DOM-to-TextContent offset mapping of a block. It adds
the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_result.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

Note 1: The patch can be made cleaner if we do not write whitespace-collapsed
strings back to LayoutText after layout.

Note 2: The built offset mapping is wrong when text-transform expands/removes
characters (e.g., ß => SS)

BUG=699017
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

[Xiaocheng, 2017-07-17 21:24:56]

I was thinking about further polishing and splitting before landing the patch.
But it turns out that there's not much to be done, so I'm going to land this CL
directly.

I'll land it on Tue (July 18 PDT) if there's no objection.

[eae, 2017-07-17 22:16:01]

On 2017/07/17 21:24:56, Xiaocheng_OOO_till_July_17 wrote:
> I was thinking about further polishing and splitting before landing the patch.
> But it turns out that there's not much to be done, so I'm going to land this
CL
> directly.
> 
> I'll land it on Tue (July 18 PDT) if there's no objection.

Sounds good to me

LGTM

[Xiaocheng, 2017-07-18 04:36:14]

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

[commit-bot: I haz the power, 2017-07-18 04:36:22]

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, 2017-07-18 06:18:51]

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

[commit-bot: I haz the power, 2017-07-18 06:18:52]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[Xiaocheng, 2017-07-18 13:32:30]

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

[commit-bot: I haz the power, 2017-07-18 13:32:39]

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, 2017-07-18 15:46:51]

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

[commit-bot: I haz the power, 2017-07-18 15:46:54]

Dry run: This issue passed the CQ dry run.

[Xiaocheng, 2017-07-18 15:54:41]

The CQ bit was checked by xiaochengh@chromium.org

[Xiaocheng, 2017-07-18 15:54:41]

The patchset sent to the CQ was uploaded after l-g-t-m from
yoichio@chromium.org, kojii@chromium.org, eae@chromium.org
Link to the patchset: https://codereview.chromium.org/2963093002/#ps220001
(title: "Fix first letter handling")

[commit-bot: I haz the power, 2017-07-18 15:54:51]

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, 2017-07-18 15:59:18]

CQ is committing da patch.

Bot data: {"patchset_id": 220001, "attempt_start_ts": 1500393281370470,
"parent_rev": "e67f7c46cba145f93519c421d7ea517314b467d7", "commit_rev":
"13b1999a87a545bcab93d66a2294758c3125a84b"}

[commit-bot: I haz the power, 2017-07-18 15:59:34]

Description was changed from

==========
Add full offset mapping construction in a block

This CL constructs the DOM-to-TextContent offset mapping of a block. It adds
the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_result.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

Note 1: The patch can be made cleaner if we do not write whitespace-collapsed
strings back to LayoutText after layout.

Note 2: The built offset mapping is wrong when text-transform expands/removes
characters (e.g., ß => SS)

BUG=699017
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng
==========

to

==========
Add full offset mapping construction in a block

This CL constructs the DOM-to-TextContent offset mapping of a block. It adds
the following API:

NGOffsetMappingResult NGInlineNode::BuildOffsetMapping() const;

See ng_offset_mapping_result.h for information about NGOffsetMappingResult.
See ng_inline_node_offset_mapping_test.cc for examples.

Note 1: The patch can be made cleaner if we do not write whitespace-collapsed
strings back to LayoutText after layout.

Note 2: The built offset mapping is wrong when text-transform expands/removes
characters (e.g., ß => SS)

BUG=699017
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_layout_ng

Review-Url: https://codereview.chromium.org/2963093002
Cr-Commit-Position: refs/heads/master@{#487489}
Committed:
https://chromium.googlesource.com/chromium/src/+/13b1999a87a545bcab93d66a2294...
==========

[commit-bot: I haz the power, 2017-07-18 15:59:35]

Committed patchset #11 (id:220001) as
https://chromium.googlesource.com/chromium/src/+/13b1999a87a545bcab93d66a2294...