Reland of Pass -no-canonical-prefixes to clang by default.

Reland of Pass -no-canonical-prefixes to clang by default. (patchset #1 id:1 of https://codereview.chromium.org/2936053003/ )

Reason for revert:
Trying again now that the compiler has been fixed.

Original issue's description:
> Revert of Pass -no-canonical-prefixes to clang by default. (patchset #3 id:40001 of https://codereview.chromium.org/2842063002/ )
> 
> Reason for revert:
> This is possibly breaking CrOS builds, see comment #30 and the updates on crbug.com/712797.
> 
> Original issue's description:
> > Pass -no-canonical-prefixes to clang by default.
> > 
> > When clang invokes its subtools, by default it passes a default
> > path to them as an absolute path. We don't really need this to
> > be absolute, and having goma stores the the command lines that
> > in its cache entry keys, which means that differing absolute
> > paths can cause cache misses. So, this CL tells clang to
> > stop doing that.
> > 
> > R=thakis@chromium.org, shinyak@chromium.org
> > BUG=706224
> > 
> > Review-Url: https://codereview.chromium.org/2842063002
> > Cr-Commit-Position: refs/heads/master@{#478859}
> > Committed: https://chromium.googlesource.com/chromium/src/+/0e8121522085f344b83cc86c514e4bfb7f7c5a22
> 
> TBR=shinyak@chromium.org,thakis@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=706224
> 
> Review-Url: https://codereview.chromium.org/2936053003
> Cr-Commit-Position: refs/heads/master@{#479193}
> Committed: https://chromium.googlesource.com/chromium/src/+/cc66e92a5fcbb8810000303fc1d93094561479a5

R=hans@chromium.org
BUG=712797

[Dirk Pranke, 2017-07-11 01:02:41]

Created Reland of Pass -no-canonical-prefixes to clang by default.

[Dirk Pranke, 2017-07-11 01:03:25]

Description was changed from

==========
Reland of Pass -no-canonical-prefixes to clang by default. (patchset #1 id:1 of
https://codereview.chromium.org/2936053003/ )

Reason for revert:
Trying again now that the compiler has been fixed.

Original issue's description:
> Revert of Pass -no-canonical-prefixes to clang by default. (patchset #3
id:40001 of https://codereview.chromium.org/2842063002/ )
> 
> Reason for revert:
> This is possibly breaking CrOS builds, see comment #30 and the updates on
crbug.com/712797.
> 
> Original issue's description:
> > Pass -no-canonical-prefixes to clang by default.
> > 
> > When clang invokes its subtools, by default it passes a default
> > path to them as an absolute path. We don't really need this to
> > be absolute, and having goma stores the the command lines that
> > in its cache entry keys, which means that differing absolute
> > paths can cause cache misses. So, this CL tells clang to
> > stop doing that.
> > 
> > R=thakis@chromium.org, shinyak@chromium.org
> > BUG=706224
> > 
> > Review-Url: https://codereview.chromium.org/2842063002
> > Cr-Commit-Position: refs/heads/master@{#478859}
> > Committed:
https://chromium.googlesource.com/chromium/src/+/0e8121522085f344b83cc86c514e...
> 
> TBR=shinyak@chromium.org,thakis@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=706224
> 
> Review-Url: https://codereview.chromium.org/2936053003
> Cr-Commit-Position: refs/heads/master@{#479193}
> Committed:
https://chromium.googlesource.com/chromium/src/+/cc66e92a5fcbb8810000303fc1d9...

TBR=shinyak@chromium.org,thakis@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=706224
==========

to

==========
Reland of Pass -no-canonical-prefixes to clang by default. (patchset #1 id:1 of
https://codereview.chromium.org/2936053003/ )

Reason for revert:
Trying again now that the compiler has been fixed.

Original issue's description:
> Revert of Pass -no-canonical-prefixes to clang by default. (patchset #3
id:40001 of https://codereview.chromium.org/2842063002/ )
> 
> Reason for revert:
> This is possibly breaking CrOS builds, see comment #30 and the updates on
crbug.com/712797.
> 
> Original issue's description:
> > Pass -no-canonical-prefixes to clang by default.
> > 
> > When clang invokes its subtools, by default it passes a default
> > path to them as an absolute path. We don't really need this to
> > be absolute, and having goma stores the the command lines that
> > in its cache entry keys, which means that differing absolute
> > paths can cause cache misses. So, this CL tells clang to
> > stop doing that.
> > 
> > R=thakis@chromium.org, shinyak@chromium.org
> > BUG=706224
> > 
> > Review-Url: https://codereview.chromium.org/2842063002
> > Cr-Commit-Position: refs/heads/master@{#478859}
> > Committed:
https://chromium.googlesource.com/chromium/src/+/0e8121522085f344b83cc86c514e...
> 
> TBR=shinyak@chromium.org,thakis@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=706224
> 
> Review-Url: https://codereview.chromium.org/2936053003
> Cr-Commit-Position: refs/heads/master@{#479193}
> Committed:
https://chromium.googlesource.com/chromium/src/+/cc66e92a5fcbb8810000303fc1d9...

R=hans@chromium.org
BUG=712797
==========

[Dirk Pranke, 2017-07-11 01:03:25]

dpranke@chromium.org changed reviewers:
+ hans@chromium.org
- shinyak@chromium.org, thakis@chromium.org

[Dirk Pranke, 2017-07-11 01:04:01]

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

[commit-bot: I haz the power, 2017-07-11 01:04:31]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[shinyak, 2017-07-11 02:21:52]

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

[shinyak, 2017-07-11 02:21:52]

lgtm

[commit-bot: I haz the power, 2017-07-11 03:52:40]

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

[commit-bot: I haz the power, 2017-07-11 03:52:41]

Dry run: This issue passed the CQ dry run.

[Dirk Pranke, 2017-07-14 00:03:44]

Abandoning this CL; I've posted a revised version to Gerrit:
https://chromium-review.googlesource.com/c/571440/.