On the bots, there's no need to link GMs into SampleApp.

We build SampleApp on the bots to make sure it's not broken, but we don't run it.  So, there's no need to link in all the GMs as samples.

This reduces the number of copies of our GMs from 4 to 3 (gm, dm, and nanobench remain).

NOTREECHECKS=true

BUG=skia:2142
R=bsalomon@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/447803002
diff --git a/gyp/bench.gyp b/gyp/bench.gyp
index 9147f40..398700f 100644
--- a/gyp/bench.gyp
+++ b/gyp/bench.gyp
@@ -9,6 +9,7 @@
       'target_name': 'nanobench',
       'type': 'executable',
       'sources': [
+        '../gm/gm.cpp',
         '../bench/GMBench.cpp',
         '../bench/SKPBench.cpp',
         '../bench/ResultsWriter.cpp',