Add support for generating external types in ComputedStyleBase.

Add support for generating external types in ComputedStyleBase.

Many members in ComputedStyle are platform types like Length or
LengthBox. We currently can't generate them because they cannot be
bitfields. This patch does several things:
1) Generate different code based on whether a field is a bitfield or not.
   This allows us to store external types without packing.
2) Add a new field template 'external' which creates getter/setters that
   return/accept references and do not do any static_casts. This allows
   us to expose external types efficiently.
3) Change "initial-keyword" to "default-value" in CSSProperties.json5 to
   make keyword fields consistent with external fields.

BUG=628043
Review-Url: https://codereview.chromium.org/2697953004
Cr-Commit-Position: refs/heads/master@{#460958}
Committed: https://chromium.googlesource.com/chromium/src/+/73670040884ced3d736cde3c452a1fab82e68f70

[shend, 2017-02-16 06:45:46]

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

[commit-bot: I haz the power, 2017-02-16 06:46:41]

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

[shend, 2017-02-16 06:50:43]

shend@chromium.org changed reviewers:
+ meade@chromium.org

[shend, 2017-02-16 06:50:44]

Hi Eddy, can you please take a preliminary look at this?

[commit-bot: I haz the power, 2017-02-16 10:29:33]

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

[commit-bot: I haz the power, 2017-02-16 10:29:34]

Dry run: Try jobs failed on following builders:
  linux_chromium_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[meade_UTC10, 2017-02-17 06:56:05]

lgtm

I think this is looking pretty good already! I only had a few minor comments.

https://codereview.chromium.org/2697953004/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/build/scripts/make_computed_style_base.py
(right):

https://codereview.chromium.org/2697953004/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/build/scripts/make_computed_style_base.py:68: #
pylint: disable=no-member
Is this a new lint that got enabled? o.O

https://codereview.chromium.org/2697953004/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/build/scripts/make_computed_style_base.py:92: # Only
pack the field if the field size is not None
nit: Does this mean when the field is used as input to ComputedStyleBaseWriter's
constructor (where the packing happens)?

Perhaps it's better to refer to the reason field_size might be none (i.e. it's
an external type)

random brainstormy ideas (some reverse the logic):
self.external_type
self.is_bitfield
self.is_class_object
self.is_class_instance

[shend, 2017-02-19 23:10:17]

https://codereview.chromium.org/2697953004/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/build/scripts/make_computed_style_base.py
(right):

https://codereview.chromium.org/2697953004/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/build/scripts/make_computed_style_base.py:68: #
pylint: disable=no-member
On 2017/02/17 at 06:56:05, Eddy wrote:
> Is this a new lint that got enabled? o.O

Urgh, the comment doesn't explain anything, I updated it. Basically, the line
'self.is_packed = self.size ...' gives a lint error because we dynamically set
all the attributes and pylint is like "what's self.size?". In a later patch, I'm
hoping to reduce the number of attributes in the Field class so I can just pass
all the arguments as normal arguments instead of kwargs.

https://codereview.chromium.org/2697953004/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/build/scripts/make_computed_style_base.py:92: # Only
pack the field if the field size is not None
On 2017/02/17 at 06:56:05, Eddy wrote:
> nit: Does this mean when the field is used as input to
ComputedStyleBaseWriter's constructor (where the packing happens)?
> 
> Perhaps it's better to refer to the reason field_size might be none (i.e. it's
an external type)
> 
> random brainstormy ideas (some reverse the logic):
> self.external_type
> self.is_bitfield
> self.is_class_object
> self.is_class_instance

Yeah "packed" is ambiguous. I changed it to 'is_bitfield' since keyword fields
can either be bitfields or not (for speed), so the name has to be generic across
different field templates.

[shend, 2017-02-19 23:10:55]

Description was changed from

==========
Add support for generating external types in ComputedStyleBase.

(WIP) Many members in ComputedStyle are platform types like Length or
LengthBox. We currently can't generate them because they cannot be
bitfields. This patch does two things:
1) Generate different code based on whether a field is packed as a
   bitfield or not. This allows us to store external types.
2) Add a new field template 'external' which creates getter/setters that
   return/accept references and do not do any static_casts. This allows
   us to expose external types efficiently.

BUG=628043
==========

to

==========
Add support for generating external types in ComputedStyleBase.

Many members in ComputedStyle are platform types like Length or
LengthBox. We currently can't generate them because they cannot be
bitfields. This patch does two things:
1) Generate different code based on whether a field is a bitfield or not.
   This allows us to store external types without packing.
2) Add a new field template 'external' which creates getter/setters that
   return/accept references and do not do any static_casts. This allows
   us to expose external types efficiently.

BUG=628043
==========

[meade_UTC10, 2017-03-01 06:40:19]

This is still lgtm btw, if you were waiting for something from me?

[shend, 2017-03-28 22:35:19]

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

[commit-bot: I haz the power, 2017-03-28 22:35:41]

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, 2017-03-28 22:38:31]

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

[commit-bot: I haz the power, 2017-03-28 22:38:34]

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

[shend, 2017-03-29 01:01:04]

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

[commit-bot: I haz the power, 2017-03-29 01:01:56]

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

[shend, 2017-03-29 01:43:20]

Description was changed from

==========
Add support for generating external types in ComputedStyleBase.

Many members in ComputedStyle are platform types like Length or
LengthBox. We currently can't generate them because they cannot be
bitfields. This patch does two things:
1) Generate different code based on whether a field is a bitfield or not.
   This allows us to store external types without packing.
2) Add a new field template 'external' which creates getter/setters that
   return/accept references and do not do any static_casts. This allows
   us to expose external types efficiently.

BUG=628043
==========

to

==========
Add support for generating external types in ComputedStyleBase.

Many members in ComputedStyle are platform types like Length or
LengthBox. We currently can't generate them because they cannot be
bitfields. This patch does several things:
1) Generate different code based on whether a field is a bitfield or not.
   This allows us to store external types without packing.
2) Add a new field template 'external' which creates getter/setters that
   return/accept references and do not do any static_casts. This allows
   us to expose external types efficiently.
3) Change "initial-keyword" to "default-value" in CSSProperties.json5 to make
keyword fields consistent with external fields.

BUG=628043
==========

[shend, 2017-03-29 01:43:30]

Description was changed from

==========
Add support for generating external types in ComputedStyleBase.

Many members in ComputedStyle are platform types like Length or
LengthBox. We currently can't generate them because they cannot be
bitfields. This patch does several things:
1) Generate different code based on whether a field is a bitfield or not.
   This allows us to store external types without packing.
2) Add a new field template 'external' which creates getter/setters that
   return/accept references and do not do any static_casts. This allows
   us to expose external types efficiently.
3) Change "initial-keyword" to "default-value" in CSSProperties.json5 to make
keyword fields consistent with external fields.

BUG=628043
==========

to

==========
Add support for generating external types in ComputedStyleBase.

Many members in ComputedStyle are platform types like Length or
LengthBox. We currently can't generate them because they cannot be
bitfields. This patch does several things:
1) Generate different code based on whether a field is a bitfield or not.
   This allows us to store external types without packing.
2) Add a new field template 'external' which creates getter/setters that
   return/accept references and do not do any static_casts. This allows
   us to expose external types efficiently.
3) Change "initial-keyword" to "default-value" in CSSProperties.json5 to
   make keyword fields consistent with external fields.

BUG=628043
==========

[commit-bot: I haz the power, 2017-03-29 03:05:26]

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

[commit-bot: I haz the power, 2017-03-29 03:05:26]

Dry run: Try jobs failed on following builders:
  ios-simulator on master.tryserver.chromium.mac (JOB_TIMED_OUT, build hasn't
started yet, builder probably lacks capacity)

[shend, 2017-03-29 22:41:21]

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

[commit-bot: I haz the power, 2017-03-29 22:41:59]

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, 2017-03-29 23:28:45]

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

[commit-bot: I haz the power, 2017-03-29 23:28:46]

Dry run: This issue passed the CQ dry run.

[shend, 2017-03-29 23:49:47]

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

[commit-bot: I haz the power, 2017-03-29 23:50:48]

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, 2017-03-30 01:52:51]

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

[commit-bot: I haz the power, 2017-03-30 01:52:51]

Dry run: Try jobs failed on following builders:
  ios-simulator on master.tryserver.chromium.mac (JOB_TIMED_OUT, build hasn't
started yet, builder probably lacks capacity)

[shend, 2017-03-30 21:49:36]

The CQ bit was checked by shend@chromium.org

[shend, 2017-03-30 21:49:36]

The patchset sent to the CQ was uploaded after l-g-t-m from meade@chromium.org
Link to the patchset: https://codereview.chromium.org/2697953004/#ps120001
(title: "remove unused macro")

[commit-bot: I haz the power, 2017-03-30 21:50:29]

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, 2017-03-31 00:46:48]

CQ is committing da patch.

Bot data: {"patchset_id": 120001, "attempt_start_ts": 1490910576593410,
"parent_rev": "60f0d3fdcd32ace98f0baafab27ee420637d3760", "commit_rev":
"73670040884ced3d736cde3c452a1fab82e68f70"}

[commit-bot: I haz the power, 2017-03-31 00:46:59]

CQ is committing da patch.

Bot data: {"patchset_id": 120001, "attempt_start_ts": 1490910576593410,
"parent_rev": "60f0d3fdcd32ace98f0baafab27ee420637d3760", "commit_rev":
"73670040884ced3d736cde3c452a1fab82e68f70"}

[commit-bot: I haz the power, 2017-03-31 00:48:08]

Description was changed from

==========
Add support for generating external types in ComputedStyleBase.

Many members in ComputedStyle are platform types like Length or
LengthBox. We currently can't generate them because they cannot be
bitfields. This patch does several things:
1) Generate different code based on whether a field is a bitfield or not.
   This allows us to store external types without packing.
2) Add a new field template 'external' which creates getter/setters that
   return/accept references and do not do any static_casts. This allows
   us to expose external types efficiently.
3) Change "initial-keyword" to "default-value" in CSSProperties.json5 to
   make keyword fields consistent with external fields.

BUG=628043
==========

to

==========
Add support for generating external types in ComputedStyleBase.

Many members in ComputedStyle are platform types like Length or
LengthBox. We currently can't generate them because they cannot be
bitfields. This patch does several things:
1) Generate different code based on whether a field is a bitfield or not.
   This allows us to store external types without packing.
2) Add a new field template 'external' which creates getter/setters that
   return/accept references and do not do any static_casts. This allows
   us to expose external types efficiently.
3) Change "initial-keyword" to "default-value" in CSSProperties.json5 to
   make keyword fields consistent with external fields.

BUG=628043

Review-Url: https://codereview.chromium.org/2697953004
Cr-Commit-Position: refs/heads/master@{#460958}
Committed:
https://chromium.googlesource.com/chromium/src/+/73670040884ced3d736cde3c452a...
==========

[commit-bot: I haz the power, 2017-03-31 00:48:09]

Committed patchset #7 (id:120001) as
https://chromium.googlesource.com/chromium/src/+/73670040884ced3d736cde3c452a...