Revert of [libfuzzer] supporting libfuzzer on mac with asan

build/config/sanitizers/BUILD.gn

Index: build/config/sanitizers/BUILD.gn
diff --git a/build/config/sanitizers/BUILD.gn b/build/config/sanitizers/BUILD.gn
index f3469e2098dbf029b3a60cece61eede689504026..850a249910330a7b734be3ed17d89d0dcf847ffa 100644
--- a/build/config/sanitizers/BUILD.gn
+++ b/build/config/sanitizers/BUILD.gn
@@ -28,17 +28,12 @@ group("deps") {
     }
     if (use_custom_libcxx) {
       deps += [ "//buildtools/third_party/libc++:libcxx_proxy" ]
-      if (is_mac) {
-        deps += [ ":copy_libclang_rt_dyn" ]
-      }
     }
   }
 }
 
 config("sanitizer_options_link_helper") {
-  if (!is_mac) {
-    ldflags = [ "-Wl,-u_sanitizer_options_link_helper" ]
-  }
+  ldflags = [ "-Wl,-u_sanitizer_options_link_helper" ]
 }
 
 source_set("options_sources") {
@@ -300,10 +295,6 @@ config("default_sanitizer_flags") {
       ]
     }
   }
-
-  if (is_mac && is_asan) {
-    libs = [ "clang_rt.asan_osx_dynamic" ]
-  }
 }
 
 config("default_sanitizer_coverage_flags") {
@@ -318,17 +309,3 @@ config("default_sanitizer_coverage_flags") {
     ]
   }
 }
-
-# Copy dynamic clang_rt sanitizer libraries to output directory.
-if (is_mac) {
-  copy("copy_libclang_rt_dyn") {
-    sources = [
-      "//third_party/llvm-build/Release+Asserts/compiler-rt/lib/darwin/libclang_rt.asan_osx_dynamic.dylib",
-      "//third_party/llvm-build/Release+Asserts/compiler-rt/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib",
-      "//third_party/llvm-build/Release+Asserts/compiler-rt/lib/darwin/libclang_rt.ubsan_osx_dynamic.dylib",
-    ]
-    outputs = [
-      "$root_build_dir/{{source_file_part}}",
-    ]
-  }
-}