Disabled more reference builds on the Nexus5X due to the TimeoutException error

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 526350bbe3cdad555a5b9e25012736b546a14663..f9702a7e020c22868bddc0113f1525724bdeb9ce 100644
--- a/tools/perf/benchmarks/smoothness.py
+++ b/tools/perf/benchmarks/smoothness.py
@@ -48,6 +48,11 @@ class SmoothnessTop25(_Smoothness):
   def Name(cls):
     return 'smoothness.top_25_smooth'
 
+  @classmethod
+  def ShouldDisable(cls, possible_browser):  # http://crbug.com/597656
+      return (possible_browser.browser_type == 'reference' and
+              possible_browser.platform.GetDeviceTypeName() == 'Nexus 5X')
+
 
 class SmoothnessToughFiltersCases(_Smoothness):
   """Measures frame rate and a variety of other statistics.
@@ -128,6 +133,10 @@ class SmoothnessKeyMobileSites(_Smoothness):
   def Name(cls):
     return 'smoothness.key_mobile_sites_smooth'
 
+  @classmethod
+  def ShouldDisable(cls, possible_browser):  # http://crbug.com/597656
+      return (possible_browser.browser_type == 'reference' and
+              possible_browser.platform.GetDeviceTypeName() == 'Nexus 5X')
 
 @benchmark.Disabled('android')  # crbug.com/589580
 @benchmark.Disabled('android-reference')  # crbug.com/588786
@@ -182,6 +191,11 @@ class SmoothnessGpuRasterizationTop25(_Smoothness):
   def Name(cls):
     return 'smoothness.gpu_rasterization.top_25_smooth'
 
+  @classmethod
+  def ShouldDisable(cls, possible_browser):  # http://crbug.com/597656
+      return (possible_browser.browser_type == 'reference' and
+              possible_browser.platform.GetDeviceTypeName() == 'Nexus 5X')
+
 
 # crbug.com/589580 (This test should only be enabled on Android after fix.)
 @benchmark.Disabled('all')
@@ -245,6 +259,11 @@ class SmoothnessSyncScrollKeyMobileSites(_Smoothness):
   def Name(cls):
     return 'smoothness.sync_scroll.key_mobile_sites_smooth'
 
+  @classmethod
+  def ShouldDisable(cls, possible_browser):  # http://crbug.com/597656
+      return (possible_browser.browser_type == 'reference' and
+              possible_browser.platform.GetDeviceTypeName() == 'Nexus 5X')
+
 
 @benchmark.Enabled('android')
 class SmoothnessSimpleMobilePages(_Smoothness):