Revert of win: Set is_clang=true by default.

Revert of win: Set is_clang=true by default. (patchset #6 id:100001 of https://codereview.chromium.org/2870543003/ )

Reason for revert:
Breaks many tests:
goma errors https://bugs.chromium.org/p/chromium/issues/detail?id=727488 
webkit_tests is https://bugs.chromium.org/p/chromium/issues/detail?id=727463 
(most of) win7 tests is https://bugs.chromium.org/p/chromium/issues/detail?id=727458 


Original issue's description:
> win: Set is_clang=true by default.
> 
> To figure out unknown problems. If this inconveniences you in any way, please
> do let us know (ideally on crbug.com) – finding annoying things are part of the
> motivation for this change.
> 
> If this breaks anything, please revert with prejudice -- but file a bug for
> us about what went wrong. We intend to revert this in 5 hours if it's not
> reverted earlier due to breaking something.
> 
> This also switches win_clang to use MSVC as compiler, to make sure things stay
> compilable with both compilers even while this is in.
> 
> Known problems:
> * build times without goma are slower (but you can do goma builds with debug
>   info, which are faster)
> * incremental linking of webcore.dll doesn't work, so if you work on blink
>   on windows links will be slow. If this affects you, please star
>   https://crbug.com/717207 and make yourself heard.
> 
> This doesn't affect what we ship, which is currently off an PGO builder.
> 
> BUG=709690, 82385
> 
> Review-Url: https://codereview.chromium.org/2870543003
> Cr-Commit-Position: refs/heads/master@{#475401}
> Committed: https://chromium.googlesource.com/chromium/src/+/d560ed865c053d87594aca8a72637593117d5d1b

TBR=hans@chromium.org,brettw@chromium.org,brucedawson@chromium.org,jam@chromium.org,thakis@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=709690, 82385
Review-Url: https://codereview.chromium.org/2907363002
Cr-Commit-Position: refs/heads/master@{#475447}
Committed: https://chromium.googlesource.com/chromium/src/+/99ce70bc4ae8d3a4c7431f875af32d978fb97965

[kjellander_chromium, 2017-05-30 07:00:49]

The CQ bit was checked by kjellander@chromium.org

[kjellander_chromium, 2017-05-30 07:00:50]

Created Revert of win: Set is_clang=true by default.

[commit-bot: I haz the power, 2017-05-30 07:01:11]

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, 2017-05-30 07:01:24]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1496127649974400, "parent_rev":
"aa263e32cadf984c2c77ea31a45d7bf39f14d8fc", "commit_rev":
"99ce70bc4ae8d3a4c7431f875af32d978fb97965"}

[commit-bot: I haz the power, 2017-05-30 07:01:36]

Description was changed from

==========
Revert of win: Set is_clang=true by default. (patchset #6 id:100001 of
https://codereview.chromium.org/2870543003/ )

Reason for revert:
Breaks many tests:
goma errors https://bugs.chromium.org/p/chromium/issues/detail?id=727488 
webkit_tests is https://bugs.chromium.org/p/chromium/issues/detail?id=727463 
(most of) win7 tests is
https://bugs.chromium.org/p/chromium/issues/detail?id=727458 


Original issue's description:
> win: Set is_clang=true by default.
> 
> To figure out unknown problems. If this inconveniences you in any way, please
> do let us know (ideally on crbug.com) – finding annoying things are part of
the
> motivation for this change.
> 
> If this breaks anything, please revert with prejudice -- but file a bug for
> us about what went wrong. We intend to revert this in 5 hours if it's not
> reverted earlier due to breaking something.
> 
> This also switches win_clang to use MSVC as compiler, to make sure things stay
> compilable with both compilers even while this is in.
> 
> Known problems:
> * build times without goma are slower (but you can do goma builds with debug
>   info, which are faster)
> * incremental linking of webcore.dll doesn't work, so if you work on blink
>   on windows links will be slow. If this affects you, please star
>   https://crbug.com/717207 and make yourself heard.
> 
> This doesn't affect what we ship, which is currently off an PGO builder.
> 
> BUG=709690,82385
> 
> Review-Url: https://codereview.chromium.org/2870543003
> Cr-Commit-Position: refs/heads/master@{#475401}
> Committed:
https://chromium.googlesource.com/chromium/src/+/d560ed865c053d87594aca8a7263...

TBR=hans@chromium.org,brettw@chromium.org,brucedawson@chromium.org,jam@chromi...
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=709690,82385
==========

to

==========
Revert of win: Set is_clang=true by default. (patchset #6 id:100001 of
https://codereview.chromium.org/2870543003/ )

Reason for revert:
Breaks many tests:
goma errors https://bugs.chromium.org/p/chromium/issues/detail?id=727488 
webkit_tests is https://bugs.chromium.org/p/chromium/issues/detail?id=727463 
(most of) win7 tests is
https://bugs.chromium.org/p/chromium/issues/detail?id=727458 


Original issue's description:
> win: Set is_clang=true by default.
> 
> To figure out unknown problems. If this inconveniences you in any way, please
> do let us know (ideally on crbug.com) – finding annoying things are part of
the
> motivation for this change.
> 
> If this breaks anything, please revert with prejudice -- but file a bug for
> us about what went wrong. We intend to revert this in 5 hours if it's not
> reverted earlier due to breaking something.
> 
> This also switches win_clang to use MSVC as compiler, to make sure things stay
> compilable with both compilers even while this is in.
> 
> Known problems:
> * build times without goma are slower (but you can do goma builds with debug
>   info, which are faster)
> * incremental linking of webcore.dll doesn't work, so if you work on blink
>   on windows links will be slow. If this affects you, please star
>   https://crbug.com/717207 and make yourself heard.
> 
> This doesn't affect what we ship, which is currently off an PGO builder.
> 
> BUG=709690,82385
> 
> Review-Url: https://codereview.chromium.org/2870543003
> Cr-Commit-Position: refs/heads/master@{#475401}
> Committed:
https://chromium.googlesource.com/chromium/src/+/d560ed865c053d87594aca8a7263...

TBR=hans@chromium.org,brettw@chromium.org,brucedawson@chromium.org,jam@chromi...
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=709690,82385

Review-Url: https://codereview.chromium.org/2907363002
Cr-Commit-Position: refs/heads/master@{#475447}
Committed:
https://chromium.googlesource.com/chromium/src/+/99ce70bc4ae8d3a4c7431f875af3...
==========

[commit-bot: I haz the power, 2017-05-30 07:01:37]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/99ce70bc4ae8d3a4c7431f875af3...

[Michael Achenbach, 2017-05-30 07:18:35]

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

[Michael Achenbach, 2017-05-30 07:18:35]

Filed also http://crbug.com/727546 for Win gpu fyi compile.