Get test running scripts to detect and report common error.

testing/tools/run_corpus_tests.py

Index: testing/tools/run_corpus_tests.py
diff --git a/testing/tools/run_corpus_tests.py b/testing/tools/run_corpus_tests.py
index 13376f78780ea82d0434a173bbdcbe015e0461ee..b5c7224bb5203e4bb16945b90c5f04dbe632390f 100755
--- a/testing/tools/run_corpus_tests.py
+++ b/testing/tools/run_corpus_tests.py
@@ -27,6 +27,10 @@ def test_one_file(input_filename, source_dir, working_dir,
   try:
     shutil.copyfile(input_path, pdf_path)
     sys.stdout.flush()
+    if not os.path.exists(pdfium_test_path):

[Tom Sepez, 2015/05/20 23:24:38]

This should move to line 49, so we do it once and not on every file to process.

+      print "FAILURE: Can't find test executable '%s'" % pdfium_test_path
+      print "Use --build-dir=out\\Release"

[Tom Sepez, 2015/05/20 23:24:38]

nit: there may be other build dirs besides just out/release, depending on how
clever the developer has been.  So maybe say
"Use the -build-dir option to search alternate locations"
or some such.

+      sys.exit(10)
     subprocess.check_call([pdfium_test_path, '--png', pdf_path])
   except subprocess.CalledProcessError as e:
     print "FAILURE: " + input_filename + "; " + str(e)