Convert //components/metal_util to use frameworks and weak_frameworks

Bug: 1052560
Change-Id: Id7546c72f246c9910eadd6edcb49b71bb9ec8d65
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2227858Reviewed-by: ccameron <ccameron@chromium.org>
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#774780}

components/metal_util/BUILD.gn

@@ -4,15 +4,6 @@
 
 import("//testing/test.gni")
 
-config("metal_weak_framework") {
-  ldflags = [
-    "-weak_framework",
-    "Metal",
-    "-weak_framework",
-    "MetalKit",
-  ]
-}
-
 component("metal_util") {
   output_name = "metal"
 
@@ -38,11 +29,14 @@ component("metal_util") {
     "//components/crash/core/common:crash_key",
   ]
 
-  libs = [
+  frameworks = [
     "Cocoa.framework",
     "IOSurface.framework",
     "QuartzCore.framework",
   ]
 
-  configs += [ ":metal_weak_framework" ]
+  weak_frameworks = [
+    "Metal.framework",
+    "MetalKit.framework",
+  ]
 }