Combine corpus runner into test_runner.py

testing/tools/pngdiffer.py

Index: testing/tools/pngdiffer.py
diff --git a/testing/tools/pngdiffer.py b/testing/tools/pngdiffer.py
index a1533b8329f4a440e5cee836ed3f0fee000d673c..aeed9af4c24e2ed43423a53591ae9a151d3bb5b2 100755
--- a/testing/tools/pngdiffer.py
+++ b/testing/tools/pngdiffer.py
@@ -57,7 +57,13 @@ class PNGDiffer():
         if i == 0:
           print "WARNING: no expected results files for " + input_filename
         break
-      print "Checking " + actual_path
+
+      short_path = actual_path
+      pos = short_path.find("pdfium/testing/")
+      if (pos != -1):
+        short_path = short_path[pos + len("pdfium/testing/"):]
+      print "Checking " + short_path
+
       sys.stdout.flush()
       if os.path.exists(expected_path):
         error = common.RunCommand(