Fix directory layout for tools/memory_inspector tests.

tools/memory_inspector/PRESUBMIT.py

Index: tools/memory_inspector/PRESUBMIT.py
diff --git a/tools/memory_inspector/PRESUBMIT.py b/tools/memory_inspector/PRESUBMIT.py
index d3e11588e810b51f54482e74e12969d5906e393b..9508ae628bcab9ebe10f994f9e1662ff4fb0f7e7 100644
--- a/tools/memory_inspector/PRESUBMIT.py
+++ b/tools/memory_inspector/PRESUBMIT.py
@@ -12,11 +12,10 @@ details on the presubmit API built into gcl.
 def CommonChecks(input_api, output_api):
   output = []
   output.extend(input_api.canned_checks.RunPylint(input_api, output_api))
-  output.extend(
-      input_api.canned_checks.RunUnitTestsInDirectory(
-          input_api, output_api,
-          input_api.os_path.join(input_api.PresubmitLocalPath(), 'tests'),
-          whitelist=[r'.+_test\.py$']))
+  output.extend(input_api.canned_checks.RunUnitTests(
+      input_api,
+      output_api,
+      [input_api.os_path.join(input_api.PresubmitLocalPath(), 'run_tests')]))
 
   if input_api.is_committing:
     output.extend(input_api.canned_checks.PanProjectChecks(input_api,