[tools/perf] fetch_benchmark_deps: Add benchmarks path 'contrib'

As the benchmark page_cycler_v2 is located under
src/tools/perf/contrib/cros_benchmarks, the patch fixes the failure
of deps searching for page_cycler_v2.typical_25 by adding the
benchmarks directory 'src/tools/perf/contrib' into search path.

BUG=728973
TEST=python src/tools/perf/fetch_benchmark_deps.py
  page_cycler_v2.typical_25 --platform=cros
Signed-off-by: Chung-yih Wang <cywang@chromium.org>
Change-Id: Id9e31488cba07bb433551b768ddaaa99e70a2b9d
Reviewed-on: https://chromium-review.googlesource.com/598127Reviewed-by: Ned Nguyen <nednguyen@google.com>
Cr-Commit-Position: refs/heads/master@{#491682}

tools/perf/fetch_benchmark_deps.py

@@ -92,9 +92,11 @@ def main(args, output):
   options = parser.parse_args(args)
 
   if options.benchmark_name:
+    perf_dir = path_util.GetPerfDir()
+    benchmark_dirs=[os.path.join(perf_dir, 'benchmarks'),
+                    os.path.join(perf_dir, 'contrib')]
     config = chromium_config.ChromiumConfig(
-        top_level_dir=path_util.GetPerfDir(),
-        benchmark_dirs=[os.path.join(path_util.GetPerfDir(), 'benchmarks')])
+        top_level_dir=path_util.GetPerfDir(), benchmark_dirs=benchmark_dirs)
     benchmark = benchmark_runner.GetBenchmarkByName(
         options.benchmark_name, config)
     if not benchmark: