Gold support in PDFiumchromium/2970

Extends the PDFium tests to collect images and meta data to be uploaded
to Gold. This feature is triggered by adding the --gold_* flags.

It extends pdfium_test to output the MD5 hash of the underlying pixel
buffer for each page it renders.
That output is then processed by test_runner.py to generate the
gold meta data.

This behavior is modeled after the 'dm' tool in skia. See
https://skia.googlesource.com/skia/+/master/dm/DM.cpp#1090

This should not cause any change in the current behavior of the tests,
it will be trigger once we update the buildbot recipe.

BUG=skia:5973

Review-Url: https://codereview.chromium.org/2578893004

1 files changed, 18 insertions, 0 deletions

diff --git a/testing/tools/common.py b/testing/tools/common.py
index 1e1d257f48..a0cc946f1a 100755
--- a/testing/tools/common.py
+++ b/testing/tools/common.py
@@ -25,6 +25,24 @@ def RunCommand(cmd):
   except subprocess.CalledProcessError as e:
     return e
 
+# RunCommandExtractHashedFiles returns a tuple: (raised_exception, hashed_files)
+# It runs the given command. If it fails it will return an exception and None.
+# If it succeeds it will return None and the list of processed files extracted
+# from the output of the command. It expects lines in this format:
+#    MD5:<path_to_image_file>:<md5_hash_in_hex>
+# The returned hashed_files is a list of (file_path, MD5-hash) pairs.
+def RunCommandExtractHashedFiles(cmd):
+  try:
+    output = subprocess.check_output(cmd, universal_newlines=True)
+    ret = []
+    for line in output.split('\n'):
+      line = line.strip()
+      if line.startswith("MD5:"):
+          ret.append([x.strip() for x in line.lstrip("MD5:").rsplit(":", 1)])
+    return None, ret
+  except subprocess.CalledProcessError as e:
+    return e, None
+
 # Adjust Dr. Memory wrapper to have separate log directory for each test
 # for better error reporting.
 def DrMemoryWrapper(wrapper, pdf_name):