[Mac/GN] Set up the component build.

This adds the required framework to libs[] wherever they are required (most
of the changes in this CL). It also enables the component build optimization
of creating a non-bundled dylib to roll up all the sources and dependencies.
The framework then links that, which allows the build to not copy the bundled
library if any sources change. This is based on the technique implemented
https://codereview.chromium.org/11420019/.

BUG=431177
R=thakis@chromium.org,brettw@chromium.org
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_optional_gpu_tests_rel;tryserver.chromium.mac:mac_optional_gpu_tests_rel;tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/1961473003
Cr-Commit-Position: refs/heads/master@{#392823}

diff --git a/third_party/decklink/BUILD.gn b/third_party/decklink/BUILD.gn
index 6847d9c..2a19582c 100644
--- a/third_party/decklink/BUILD.gn
+++ b/third_party/decklink/BUILD.gn

@@ -8,5 +8,9 @@
     sources = [
       "mac/include/DeckLinkAPIDispatch.cpp",
     ]
+    libs = [
+      "CoreFoundation.framework",
+      "IOKit.framework",
+    ]
   }
 }