[Mac/GN] Do not specify any default_libs to link.

This is the wrong thing to do. Targets should have control over what they link,
since adding frameworks can have run-time side effects. The only library that is
required is libSystem.dylib, but the linker implicitly adds that unless it
is creating a static executable.

BUG=431177

Review URL: https://codereview.chromium.org/1902593003

Cr-Original-Commit-Position: refs/heads/master@{#389111}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 4806ea270d3151fddb36117261fbebb28ecbb2c4

config/BUILD.gn

@@ -355,16 +355,9 @@ config("default_libs") {
       "m",
     ]
   } else if (is_mac) {
-    libs = [
-      "AppKit.framework",
-      "ApplicationServices.framework",
-      "Carbon.framework",
-      "CoreFoundation.framework",
-      "Foundation.framework",
-      "IOKit.framework",
-      "OpenGL.framework",
-      "Security.framework",
-    ]
+    # Targets should choose to explicitly link frameworks they require. Since
+    # linking can have run-time side effects, nothing should be listed here.
+    libs = []
   } else if (is_ios) {
     # The libraries listed here will be specified for both the target and the
     # host. Only the common ones should be listed here.