apple: Convert GN libs lists to frameworks in //third_party.

GN recently added support for Apple frameworks to link, rather than
overloading the libs lists. This pulls .frameworks out of the libs
lists, so that GN can stop supporting .frameworks in libs in the
future.

Bug: 1052560
Change-Id: Id1795920fc9ed2de9a5413f6aa9ed3cd97c23707
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2277112
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Auto-Submit: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#784520}

diff --git a/third_party/decklink/BUILD.gn b/third_party/decklink/BUILD.gn
index 4c0fa42..2ca860e 100644
--- a/third_party/decklink/BUILD.gn
+++ b/third_party/decklink/BUILD.gn

@@ -5,7 +5,7 @@
 if (is_mac) {
   static_library("decklink") {
     sources = [ "mac/include/DeckLinkAPIDispatch.cpp" ]
-    libs = [
+    frameworks = [
       "CoreFoundation.framework",
       "IOKit.framework",
     ]