fix android framework build for nanobench

R=mtklein@google.com, tomhudson@chromium.org, tomhudson@google.com

Author: djsollen@google.com

Review URL: https://codereview.chromium.org/495003004
diff --git a/gyp/bench.gyp b/gyp/bench.gyp
index 4988169..d2eb1ea 100644
--- a/gyp/bench.gyp
+++ b/gyp/bench.gyp
@@ -26,6 +26,13 @@
         'tools.gyp:proc_stats',
         'tools.gyp:timer',
       ],
+      'conditions': [
+        ['skia_android_framework', {
+          'libraries': [
+            '-lskia',
+          ],
+        }],
+      ],
     },
   ],
 }