Moves WEBRTC_POSIX define from header file to gyp-settings.

Makes WEBRTC_POSIX defined in the same place as the other OSs also this is needed to prevent excessive changes to talk/base files when migrating them to webrtc/base

BUG=N/A
R=andrew@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/9499004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5659 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/build/common.gypi b/webrtc/build/common.gypi
index d8b958a..9e4a305 100644
--- a/webrtc/build/common.gypi
+++ b/webrtc/build/common.gypi
@@ -261,6 +261,13 @@
           }],
         ],
       }],
+      ['os_posix==1', {
+        # For access to standard POSIXish features, use WEBRTC_POSIX instead of
+        # a more specific macro.
+        'defines': [
+          'WEBRTC_POSIX',
+        ],
+      }],
       ['OS=="ios"', {
         'defines': [
           'WEBRTC_MAC',
diff --git a/webrtc/typedefs.h b/webrtc/typedefs.h
index 16e2a9f..4857908 100644
--- a/webrtc/typedefs.h
+++ b/webrtc/typedefs.h
@@ -14,13 +14,6 @@
 #ifndef WEBRTC_TYPEDEFS_H_
 #define WEBRTC_TYPEDEFS_H_
 
-// For access to standard POSIXish features, use WEBRTC_POSIX instead of a
-// more specific macro.
-#if defined(WEBRTC_MAC) || defined(WEBRTC_LINUX) || \
-    defined(WEBRTC_ANDROID)
-#define WEBRTC_POSIX
-#endif
-
 // Processor architecture detection.  For more info on what's defined, see:
 //   http://msdn.microsoft.com/en-us/library/b0084kay.aspx
 //   http://www.agner.org/optimize/calling_conventions.pdf