Move syncer::kModelTypeInfoMap array to read-only data segment

Move syncer::kModelTypeInfoMap array to read-only data segment

Due to a quirk in VC++ it is easy to accidentally prevent a const global
array from being placed in the read-only data segment. This change
removes some should-be-harmless 'const' keywords to work around this
quirk and move ~960 bytes to the .rdata (read-only) data segment in
chrome.dll.

VC++ bug is filed here:
https://connect.microsoft.com/VisualStudio/feedback/details/3117602

Other instances of this quirk are also being worked around.

BUG=677351
Committed: https://crrev.com/f647c9f14b76450131f88d99c186010d960aeccf
Cr-Commit-Position: refs/heads/master@{#441250}

[brucedawson, 2016-12-29 22:22:50]

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

[commit-bot: I haz the power, 2016-12-29 22:23:01]

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

[brucedawson, 2016-12-29 22:23:29]

Description was changed from

==========
Move syncer::kModelTypeInfoMap array to read-only data segment

Due to a quirk in VC++ it is easy to accidentally prevent a const global
array from being placed in the read-only data segment. This change
removes some should-be-harmless 'const' keywords to work around this
quirk and move ~960 bytes to the .rdata (read-only) data segment in
chrome.dll.

VC++ bug is filed here:
https://connect.microsoft.com/VisualStudio/feedback/details/3117602

Other instances of this quirk are also being worked around.

BUG=677351
==========

to

==========
Move syncer::kModelTypeInfoMap array to read-only data segment

Due to a quirk in VC++ it is easy to accidentally prevent a const global
array from being placed in the read-only data segment. This change
removes some should-be-harmless 'const' keywords to work around this
quirk and move ~960 bytes to the .rdata (read-only) data segment in
chrome.dll.

VC++ bug is filed here:
https://connect.microsoft.com/VisualStudio/feedback/details/3117602

Other instances of this quirk are also being worked around.

BUG=677351
==========

[brucedawson, 2016-12-29 22:23:29]

brucedawson@chromium.org changed reviewers:
+ stanisc@chromium.org

[commit-bot: I haz the power, 2016-12-29 23:15:29]

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

[commit-bot: I haz the power, 2016-12-29 23:15:29]

Dry run: This issue passed the CQ dry run.

[stanisc, 2017-01-03 19:57:00]

Would it be better to use a #define that get resolved as nothing on Windows and
const on other platforms?

I think the reason const was used in this struct is to convey that these fields
get initialized once and never changed. Without const that is less obvious.

[brucedawson, 2017-01-03 20:35:15]

On 2017/01/03 19:57:00, stanisc wrote:
> Would it be better to use a #define that get resolved as nothing on Windows
and
> const on other platforms?
> 
> I think the reason const was used in this struct is to convey that these
fields
> get initialized once and never changed. Without const that is less obvious.

It looks like ModelTypeInfo is only used to declare the one array and that
entire array is const, which means the hint doesn't have much value.

That is, we could use a #define but is there enough value to justify the
ugliness?

[stanisc, 2017-01-03 21:48:15]

Well, either way is fine with me. I agree that this struct is local to this file
so it should be easy to see that the data is actually const by construction.

lgtm

[brucedawson, 2017-01-03 21:55:32]

The CQ bit was checked by brucedawson@chromium.org

[commit-bot: I haz the power, 2017-01-03 21:56:04]

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, 2017-01-03 23:27:02]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1483480532902860, "parent_rev":
"cc9fc63c2e88476cc28742640bf0eb24d81064b7", "commit_rev":
"33691e168b6060a35dabc80aa4f471e2f1db90dd"}

[commit-bot: I haz the power, 2017-01-03 23:27:28]

Description was changed from

==========
Move syncer::kModelTypeInfoMap array to read-only data segment

Due to a quirk in VC++ it is easy to accidentally prevent a const global
array from being placed in the read-only data segment. This change
removes some should-be-harmless 'const' keywords to work around this
quirk and move ~960 bytes to the .rdata (read-only) data segment in
chrome.dll.

VC++ bug is filed here:
https://connect.microsoft.com/VisualStudio/feedback/details/3117602

Other instances of this quirk are also being worked around.

BUG=677351
==========

to

==========
Move syncer::kModelTypeInfoMap array to read-only data segment

Due to a quirk in VC++ it is easy to accidentally prevent a const global
array from being placed in the read-only data segment. This change
removes some should-be-harmless 'const' keywords to work around this
quirk and move ~960 bytes to the .rdata (read-only) data segment in
chrome.dll.

VC++ bug is filed here:
https://connect.microsoft.com/VisualStudio/feedback/details/3117602

Other instances of this quirk are also being worked around.

BUG=677351

Review-Url: https://codereview.chromium.org/2605393002
==========

[commit-bot: I haz the power, 2017-01-03 23:27:28]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2017-01-03 23:30:58]

Description was changed from

==========
Move syncer::kModelTypeInfoMap array to read-only data segment

Due to a quirk in VC++ it is easy to accidentally prevent a const global
array from being placed in the read-only data segment. This change
removes some should-be-harmless 'const' keywords to work around this
quirk and move ~960 bytes to the .rdata (read-only) data segment in
chrome.dll.

VC++ bug is filed here:
https://connect.microsoft.com/VisualStudio/feedback/details/3117602

Other instances of this quirk are also being worked around.

BUG=677351

Review-Url: https://codereview.chromium.org/2605393002
==========

to

==========
Move syncer::kModelTypeInfoMap array to read-only data segment

Due to a quirk in VC++ it is easy to accidentally prevent a const global
array from being placed in the read-only data segment. This change
removes some should-be-harmless 'const' keywords to work around this
quirk and move ~960 bytes to the .rdata (read-only) data segment in
chrome.dll.

VC++ bug is filed here:
https://connect.microsoft.com/VisualStudio/feedback/details/3117602

Other instances of this quirk are also being worked around.

BUG=677351

Committed: https://crrev.com/f647c9f14b76450131f88d99c186010d960aeccf
Cr-Commit-Position: refs/heads/master@{#441250}
==========

[commit-bot: I haz the power, 2017-01-03 23:30:59]

Patchset 1 (id:??) landed as
https://crrev.com/f647c9f14b76450131f88d99c186010d960aeccf
Cr-Commit-Position: refs/heads/master@{#441250}