Add unit test for decoder test_vector_test

Got 61 test vectors from vp8-test-vectors.git
(http://git.chromium.org/gitweb/?p=webm/vp8-test-vectors.git)

Added decoder test vectors downloading in unit tests. Uploaded
the test vectors and their md5 files to WebM website.
  $ gsutil cp *.* gs://downloads.webmproject.org/test_data/libvpx

Added their sha1sum to the test/test-data.sha1 file.

In unit tests, download the test vectors to LIBVPX_TEST_DATA_PATH.

Test_vector_test goes through the test vectors, decodes them, and
compute the md5 checksums. The checksums are compared with the
expected md5 checksums to tell if the decoder decodes correctly.

Change-Id: Ia1e84f9347ddf1d4a02e056c0fee7d28dccfae15

test/video_source.h

@@ -10,11 +10,27 @@
 #ifndef TEST_VIDEO_SOURCE_H_
 #define TEST_VIDEO_SOURCE_H_
 
+#include <cstdio>
+#include <cstdlib>
+#include <string>
 #include "test/acm_random.h"
 #include "vpx/vpx_encoder.h"
 
 namespace libvpx_test {
 
+static FILE *OpenTestDataFile(const std::string& file_name) {
+  std::string path_to_source = file_name;
+  const char *kDataPath = getenv("LIBVPX_TEST_DATA_PATH");
+
+  if (kDataPath) {
+    path_to_source = kDataPath;
+    path_to_source += "/";
+    path_to_source += file_name;
+  }
+
+  return fopen(path_to_source.c_str(), "rb");
+}
+
 // Abstract base class for test video sources, which provide a stream of
 // vpx_image_t images with associated timestamps and duration.
 class VideoSource {
@@ -128,6 +144,27 @@ class RandomVideoSource : public DummyVideoSource {
   int seed_;
 };
 
+// Abstract base class for test video sources, which provide a stream of
+// decompressed images to the decoder.
+class CompressedVideoSource {
+ public:
+  virtual ~CompressedVideoSource() {}
+
+  virtual void Init() = 0;
+
+  // Prepare the stream for reading, rewind/open as necessary.
+  virtual void Begin() = 0;
+
+  // Advance the cursor to the next frame
+  virtual void Next() = 0;
+
+  virtual const uint8_t *cxdata() const = 0;
+
+  virtual const unsigned int frame_size() const = 0;
+
+  virtual const unsigned int frame_number() const = 0;
+};
+
 }  // namespace libvpx_test
 
 #endif  // TEST_VIDEO_SOURCE_H_