Telemetry: Fix exact_matches in telemetry.test_runner.

content/test/gpu/gpu_tests/pixel.py

Index: content/test/gpu/gpu_tests/pixel.py
diff --git a/content/test/gpu/gpu_tests/pixel.py b/content/test/gpu/gpu_tests/pixel.py
index 90fcaa619dc263f5d8b4b598b6380eaf0b6c69b6..dab122c1ee5c7eb8bb9d59eb6b8a05d57a60414d 100644
--- a/content/test/gpu/gpu_tests/pixel.py
+++ b/content/test/gpu/gpu_tests/pixel.py
@@ -151,6 +151,10 @@ class Pixel(cloud_storage_test_base.TestBase):
   page_set = page_sets.PixelTestsPageSet
 
   @classmethod
+  def Name(cls):
+    return "pixel"
+
+  @classmethod
   def AddTestCommandLineArgs(cls, group):
     super(Pixel, cls).AddTestCommandLineArgs(group)
     group.add_option('--reference-dir',