Fix g++ builds by avoiding early HeapSupplement<Document> instantiation.

Fix g++ builds by avoiding early HeapSupplement<Document> instantiation.

Building ToT with g++ (component build) currently breaks when using
the Oilpan type HeapSupplement<Document>:

 ...
 error: type attributes ignored after type is already defined [-Werror=attributes]
 ...
 .../dom/Document.h:179:51: note: in expansion of macro ‘WillBeHeapSupplement’
 extern template class CORE_EXTERN_TEMPLATE_EXPORT WillBeHeapSupplement<Document>;

It appears that g++ cannot be kept happy if it implicitly instantiates
a template at a type and then later sees an extern decl like the above
with some extra attributes attached.

Hence, bring the required types into scope for FontFaceSet's declaration
to avoid that unfortunate situation.

R=haraken,thakis
BUG=

Committed: https://crrev.com/6b5fd4d088d1eafe2f375a3b0f495aab26283cc0
Cr-Commit-Position: refs/heads/master@{#371270}

[sof, 2016-01-25 15:47:02]

sigbjornf@opera.com changed reviewers:
+ mostynb@opera.com, oilpan-reviews@chromium.org

[sof, 2016-01-25 15:47:03]

please take a look.

(Cc:ing dcheng, thakis + tasak who I believe have run up into similar compat
toolchain issues in the past.)

[sof, 2016-01-25 15:47:18]

Description was changed from

==========
Fix g++ building by avoiding early HeapSupplement<Document> instantiation.

Building ToT with g++ (component build) currently breaks when using
the Oilpan type HeapSupplement<Document>:

 ...
 error: type attributes ignored after type is already defined
[-Werror=attributes]
 ...
 .../dom/Document.h:179:51: note: in expansion of macro ‘WillBeHeapSupplement’
 extern template class CORE_EXTERN_TEMPLATE_EXPORT
WillBeHeapSupplement<Document>;

It appears that g++ cannot be kept happy if it implicitly instantiates
a template at a type and then later sees an extern decl like the above
with some extra attributes attached.

Hence, bring the required types into scope for FontFaceSet's declaration
to avoid that unfortunate situation.

R=
BUG=
==========

to

==========
Fix g++ builds by avoiding early HeapSupplement<Document> instantiation.

Building ToT with g++ (component build) currently breaks when using
the Oilpan type HeapSupplement<Document>:

 ...
 error: type attributes ignored after type is already defined
[-Werror=attributes]
 ...
 .../dom/Document.h:179:51: note: in expansion of macro ‘WillBeHeapSupplement’
 extern template class CORE_EXTERN_TEMPLATE_EXPORT
WillBeHeapSupplement<Document>;

It appears that g++ cannot be kept happy if it implicitly instantiates
a template at a type and then later sees an extern decl like the above
with some extra attributes attached.

Hence, bring the required types into scope for FontFaceSet's declaration
to avoid that unfortunate situation.

R=
BUG=
==========

[Nico, 2016-01-25 15:52:15]

thakis@chromium.org changed reviewers:
+ thakis@chromium.org

[Nico, 2016-01-25 15:52:15]

Huh, I thought usually the take-away is "don't use `extern template`". Isn't
Document.h gigantic? Or am I confusing it with a different header? If it's that
header, not being able to forward-declare Document would be a bit of a problem.

[sof, 2016-01-25 15:56:21]

On 2016/01/25 15:52:15, Nico wrote:
> Huh, I thought usually the take-away is "don't use `extern template`". Isn't
> Document.h gigantic? Or am I confusing it with a different header? If it's
that
> header, not being able to forward-declare Document would be a bit of a
problem.

Document.h is a gigantic bundle of wax and it is fine to forward declare
Document. Just not when you use it conjunction with HeapSupplement<>, like here.
Says g++.

[haraken, 2016-01-25 16:00:35]

Some background: This CL is necessary to fix an issue caused by enabling Oilpan
on ToT. To minimize the confusion on developers, I want to avoid reverting
Oilpan as much as possible. So I'd be happy if you could approve this fix if it
is not doing a wrong thing :)

[Mostyn Bramley-Moore, 2016-01-25 16:05:09]

g++ builds WFM again with this patch.

[haraken, 2016-01-25 16:26:24]

LGTM on my side.

[Nico, 2016-01-25 17:22:23]

lgtm to pacify compilers after the oilpan fix, but maybe there's a more
structural long-term fix here

[sof, 2016-01-25 18:30:59]

On 2016/01/25 17:22:23, Nico wrote:
> lgtm to pacify compilers after the oilpan fix, but maybe there's a more
> structural long-term fix here

thanks, moving the "extern template" out of Document.h might be an alternative,
but it feels unnatural. tasak@ may very well have some ideas.

[sof, 2016-01-25 18:31:15]

Description was changed from

==========
Fix g++ builds by avoiding early HeapSupplement<Document> instantiation.

Building ToT with g++ (component build) currently breaks when using
the Oilpan type HeapSupplement<Document>:

 ...
 error: type attributes ignored after type is already defined
[-Werror=attributes]
 ...
 .../dom/Document.h:179:51: note: in expansion of macro ‘WillBeHeapSupplement’
 extern template class CORE_EXTERN_TEMPLATE_EXPORT
WillBeHeapSupplement<Document>;

It appears that g++ cannot be kept happy if it implicitly instantiates
a template at a type and then later sees an extern decl like the above
with some extra attributes attached.

Hence, bring the required types into scope for FontFaceSet's declaration
to avoid that unfortunate situation.

R=
BUG=
==========

to

==========
Fix g++ builds by avoiding early HeapSupplement<Document> instantiation.

Building ToT with g++ (component build) currently breaks when using
the Oilpan type HeapSupplement<Document>:

 ...
 error: type attributes ignored after type is already defined
[-Werror=attributes]
 ...
 .../dom/Document.h:179:51: note: in expansion of macro ‘WillBeHeapSupplement’
 extern template class CORE_EXTERN_TEMPLATE_EXPORT
WillBeHeapSupplement<Document>;

It appears that g++ cannot be kept happy if it implicitly instantiates
a template at a type and then later sees an extern decl like the above
with some extra attributes attached.

Hence, bring the required types into scope for FontFaceSet's declaration
to avoid that unfortunate situation.

R=haraken,thakis
BUG=
==========

[sof, 2016-01-25 18:31:22]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2016-01-25 18:33:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1634683002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1634683002/1

[commit-bot: I haz the power, 2016-01-25 18:38:57]

Description was changed from

==========
Fix g++ builds by avoiding early HeapSupplement<Document> instantiation.

Building ToT with g++ (component build) currently breaks when using
the Oilpan type HeapSupplement<Document>:

 ...
 error: type attributes ignored after type is already defined
[-Werror=attributes]
 ...
 .../dom/Document.h:179:51: note: in expansion of macro ‘WillBeHeapSupplement’
 extern template class CORE_EXTERN_TEMPLATE_EXPORT
WillBeHeapSupplement<Document>;

It appears that g++ cannot be kept happy if it implicitly instantiates
a template at a type and then later sees an extern decl like the above
with some extra attributes attached.

Hence, bring the required types into scope for FontFaceSet's declaration
to avoid that unfortunate situation.

R=haraken,thakis
BUG=
==========

to

==========
Fix g++ builds by avoiding early HeapSupplement<Document> instantiation.

Building ToT with g++ (component build) currently breaks when using
the Oilpan type HeapSupplement<Document>:

 ...
 error: type attributes ignored after type is already defined
[-Werror=attributes]
 ...
 .../dom/Document.h:179:51: note: in expansion of macro ‘WillBeHeapSupplement’
 extern template class CORE_EXTERN_TEMPLATE_EXPORT
WillBeHeapSupplement<Document>;

It appears that g++ cannot be kept happy if it implicitly instantiates
a template at a type and then later sees an extern decl like the above
with some extra attributes attached.

Hence, bring the required types into scope for FontFaceSet's declaration
to avoid that unfortunate situation.

R=haraken,thakis
BUG=
==========

[commit-bot: I haz the power, 2016-01-25 18:38:58]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-01-25 18:39:52]

Description was changed from

==========
Fix g++ builds by avoiding early HeapSupplement<Document> instantiation.

Building ToT with g++ (component build) currently breaks when using
the Oilpan type HeapSupplement<Document>:

 ...
 error: type attributes ignored after type is already defined
[-Werror=attributes]
 ...
 .../dom/Document.h:179:51: note: in expansion of macro ‘WillBeHeapSupplement’
 extern template class CORE_EXTERN_TEMPLATE_EXPORT
WillBeHeapSupplement<Document>;

It appears that g++ cannot be kept happy if it implicitly instantiates
a template at a type and then later sees an extern decl like the above
with some extra attributes attached.

Hence, bring the required types into scope for FontFaceSet's declaration
to avoid that unfortunate situation.

R=haraken,thakis
BUG=
==========

to

==========
Fix g++ builds by avoiding early HeapSupplement<Document> instantiation.

Building ToT with g++ (component build) currently breaks when using
the Oilpan type HeapSupplement<Document>:

 ...
 error: type attributes ignored after type is already defined
[-Werror=attributes]
 ...
 .../dom/Document.h:179:51: note: in expansion of macro ‘WillBeHeapSupplement’
 extern template class CORE_EXTERN_TEMPLATE_EXPORT
WillBeHeapSupplement<Document>;

It appears that g++ cannot be kept happy if it implicitly instantiates
a template at a type and then later sees an extern decl like the above
with some extra attributes attached.

Hence, bring the required types into scope for FontFaceSet's declaration
to avoid that unfortunate situation.

R=haraken,thakis
BUG=

Committed: https://crrev.com/6b5fd4d088d1eafe2f375a3b0f495aab26283cc0
Cr-Commit-Position: refs/heads/master@{#371270}
==========

[commit-bot: I haz the power, 2016-01-25 18:39:53]

Patchset 1 (id:??) landed as
https://crrev.com/6b5fd4d088d1eafe2f375a3b0f495aab26283cc0
Cr-Commit-Position: refs/heads/master@{#371270}