android: Add interactive surface statistics viewer

build/android/pylib/surface_stats_collector.py

Index: build/android/pylib/surface_stats_collector.py
diff --git a/build/android/pylib/surface_stats_collector.py b/build/android/pylib/surface_stats_collector.py
index fbd4e40c7aed06290a1b3e5f8c75e8494dce6956..ddbea2746eaee14b7c401aad78d042d95dbd4923 100644
--- a/build/android/pylib/surface_stats_collector.py
+++ b/build/android/pylib/surface_stats_collector.py
@@ -37,6 +37,10 @@ class SurfaceStatsCollector(object):
     self._data_queue = None
     self._stop_event = None
     self._results = []
+    self._warn_about_empty_data = True
+
+  def DisableWarningAboutEmptyData(self):
+    self._warn_about_empty_data = False
 
   def Start(self):
     assert not self._collector_thread
@@ -58,6 +62,12 @@ class SurfaceStatsCollector(object):
       self._collector_thread.join()
       self._collector_thread = None
 
+  def SampleResults(self):
+    self._StorePerfResults()
+    results = self._results
+    self._results = []
+    return results
+
   def GetResults(self):
     return self._results
 
@@ -77,7 +87,8 @@ class SurfaceStatsCollector(object):
       assert self._collector_thread
       (refresh_period, timestamps) = self._GetDataFromThread()
       if not refresh_period or not len(timestamps) >= 3:
-        logging.warning('Surface stat data is empty')
+        if self._warn_about_empty_data:
+          logging.warning('Surface stat data is empty')
         return
       frame_count = len(timestamps)
       seconds = timestamps[-1] - timestamps[0]