GN: Fix invalid configuration for Android GCC build.

GN: Fix invalid configuration for Android GCC build.

The disabling of the sin,cos,sinf,cosf functions had the wrong
condition for GN. This fixes that and also makes the condition
in common.gypi a bit more readable.

BUG=
R=pbos@webrtc.org

Committed: https://chromium.googlesource.com/external/webrtc/+/c0c7d2e1ef1deebde1578cd6fea6512ba2d73c45

[kjellander_webrtc, 2015-09-07 07:05:52]

kjellander@webrtc.org changed reviewers:
+ pbos@webrtc.org

[pbos-webrtc, 2015-09-07 08:27:28]

lgtm

https://codereview.webrtc.org/1307633008/diff/1/webrtc/BUILD.gn
File webrtc/BUILD.gn (right):

https://codereview.webrtc.org/1307633008/diff/1/webrtc/BUILD.gn#newcode156
webrtc/BUILD.gn:156: # TODO(kjellander): Handle warnings on Windows where WebRTC
differ from the
(Should this TODO be here?)

[kjellander_webrtc, 2015-09-07 10:57:10]

https://codereview.webrtc.org/1307633008/diff/1/webrtc/BUILD.gn
File webrtc/BUILD.gn (right):

https://codereview.webrtc.org/1307633008/diff/1/webrtc/BUILD.gn#newcode156
webrtc/BUILD.gn:156: # TODO(kjellander): Handle warnings on Windows where WebRTC
differ from the
On 2015/09/07 08:27:28, pbos-webrtc wrote:
> (Should this TODO be here?)

No, it comes from the time when I created the GN configs but Windows wasn't
fully supported yet. Today we have GN bots on Windows so this must be obsolete.
Removed in PS#2.

[kjellander_webrtc, 2015-09-07 10:58:04]

Committed patchset #2 (id:20001) manually as
c0c7d2e1ef1deebde1578cd6fea6512ba2d73c45 (presubmit successful).