Adding a test for measuring memory usage.

tools/telemetry/telemetry/multi_page_benchmark_unittest.py

Index: tools/telemetry/telemetry/multi_page_benchmark_unittest.py
diff --git a/tools/telemetry/telemetry/multi_page_benchmark_unittest.py b/tools/telemetry/telemetry/multi_page_benchmark_unittest.py
index ca59014933b1b9599faa9fc3a90f4405ccd816cc..8e2445ec48b0c78cd903e3e3dbc866862eba3b74 100644
--- a/tools/telemetry/telemetry/multi_page_benchmark_unittest.py
+++ b/tools/telemetry/telemetry/multi_page_benchmark_unittest.py
@@ -6,6 +6,7 @@ import os
 from telemetry import multi_page_benchmark
 from telemetry import multi_page_benchmark_unittest_base
 from telemetry import page as page_module
+from telemetry import page_interaction
 from telemetry import page_set
 from telemetry import wpr_modes
 
@@ -33,10 +34,18 @@ class BenchForReplay(multi_page_benchmark.MultiPageBenchmark):
     if '404 Not Found' in contents.strip():
       raise multi_page_benchmark.MeasurementFailure('Page not in archive.')
 
+class BenchWithInteraction(multi_page_benchmark.MultiPageBenchmark):
+  def GetInteractionName(self):
+    return 'test_interaction'
+
+  def MeasurePage(self, page, tab, results):
+    pass
+
 class MultiPageBenchmarkUnitTest(
   multi_page_benchmark_unittest_base.MultiPageBenchmarkUnitTestBase):
 
   _wpr_mode = wpr_modes.WPR_OFF
+  _interaction_called = False
 
   def CustomizeOptionsForTest(self, options):
     options.wpr_mode = self._wpr_mode
@@ -90,3 +99,15 @@ class MultiPageBenchmarkUnitTest(
     finally:
       if os.path.isfile(test_archive):
         os.remove(test_archive)
+
+  def testInteractions(self):
+    class MockInteraction(page_interaction.PageInteraction):
+      def PerformInteraction(self, page, tab):
+        MultiPageBenchmarkUnitTest._interaction_called = True
+    page_interaction.RegisterClass('mock', MockInteraction)
+
+    ps = self.CreatePageSetFromFileInUnittestDataDir('blank.html')
+    setattr(ps.pages[0], 'test_interaction', {'action': 'mock'})
+    benchmark = BenchWithInteraction()
+    self.RunBenchmark(benchmark, ps)
+    self.assertTrue(MultiPageBenchmarkUnitTest._interaction_called)