Disable -Wl,--as-needed in sanitizer mode.

Disable -Wl,--as-needed in sanitizer mode.

We've had problems with this linker flag in --as-needed a few times now;
just disable it if we're doing a sanitizer build.

BUG=452105
Committed: https://crrev.com/009e710e139692929e181400bcc97c71235b892e
Cr-Commit-Position: refs/heads/master@{#313321}

[Elliot Glaysher, 2015-01-27 00:49:34]

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

[Elliot Glaysher, 2015-01-27 00:49:35]

Nico: This flag has caused problems with clock_gettime() in the past, on top of
the current issues. I tried a patch which just removed optimization in mojo
(https://codereview.chromium.org/875523002/), but jamesr@ suggested that I just
disable it everywhere when |using_sanitizer|, like we do with
-fomit-frame-pointer. WDYT?

[Nico, 2015-01-27 04:39:38]

lgtm, given that this matches what the gyp build does

https://codereview.chromium.org/882443003/diff/1/build/config/compiler/BUILD.gn
File build/config/compiler/BUILD.gn (right):

https://codereview.chromium.org/882443003/diff/1/build/config/compiler/BUILD....
build/config/compiler/BUILD.gn:955: # As needed has a history of having problems
with asan. See 234010 and
fwiw,i like the comment in build/common.gypi more (
https://code.google.com/p/chromium/codesearch#chromium/src/build/common.gypi&...
)

[Elliot Glaysher, 2015-01-27 18:17:42]

The CQ bit was checked by erg@chromium.org

[commit-bot: I haz the power, 2015-01-27 18:18:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/882443003/20001

[commit-bot: I haz the power, 2015-01-27 19:09:30]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-01-27 19:10:36]

Patchset 2 (id:??) landed as
https://crrev.com/009e710e139692929e181400bcc97c71235b892e
Cr-Commit-Position: refs/heads/master@{#313321}