Temporarily disable the reference build on benchmarks using top_25.

tools/perf/benchmarks/smoothness.py

Index: tools/perf/benchmarks/smoothness.py
diff --git a/tools/perf/benchmarks/smoothness.py b/tools/perf/benchmarks/smoothness.py
index 3386369f454eb243f74ade9788d4a912585b018e..2a639284f2e56b725df8865c7d9c83d6bd3c5718 100644
--- a/tools/perf/benchmarks/smoothness.py
+++ b/tools/perf/benchmarks/smoothness.py
@@ -36,6 +36,7 @@ class _Smoothness(perf_benchmark.PerfBenchmark):
     return True
 
 
+@benchmark.Disabled('reference') # crbug.com/547833
 class SmoothnessTop25(_Smoothness):
   """Measures rendering statistics while scrolling down the top 25 web pages.
 
@@ -155,6 +156,7 @@ class SmoothnessKeySilkCases(_Smoothness):
 
 
 @benchmark.Enabled('android', 'mac')
+@benchmark.Disabled('reference') # crbug.com/547833
 class SmoothnessGpuRasterizationTop25(_Smoothness):
   """Measures rendering statistics for the top 25 with GPU rasterization.
   """