Mac Video Capture: Add Blackmagic DeckLink SDK for Mac to third_party folder

third_party/decklink/decklink.gyp

Index: third_party/decklink/decklink.gyp
diff --git a/third_party/decklink/decklink.gyp b/third_party/decklink/decklink.gyp
new file mode 100644
index 0000000000000000000000000000000000000000..a9669b2602877c5a7f077acfcfd7654db875266d
--- /dev/null
+++ b/third_party/decklink/decklink.gyp
@@ -0,0 +1,19 @@
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+  'conditions': [
+    ['OS=="mac"', {
+      'targets': [
+        {
+          'target_name': 'decklink',
+          'type': 'static_library',
+          'sources' : [
+            'mac/include/DeckLinkAPIDispatch.cpp',
+          ],
+        },  # target decklink
+      ]
+     }],
+  ]
+}