Use SKIA_OUT variable in make.py

R=djsollen@google.com

Review URL: https://codereview.chromium.org/19743005

git-svn-id: http://skia.googlecode.com/svn/trunk@10272 2bbb7eff-a529-9590-31e7-b0007b416f81

make.py

@@ -26,7 +26,7 @@ TARGET_DEFAULT = 'most'
 TARGET_GYP     = 'gyp'
 
 SCRIPT_DIR = os.path.abspath(os.path.dirname(__file__))
-OUT_SUBDIR = 'out'
+OUT_SUBDIR = os.environ.get('SKIA_OUT', 'out')
 GYP_SUBDIR = 'gyp'