Revert of [libfuzzer] supporting libfuzzer on mac with asan

build/config/sanitizers/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 
 # Contains the dependencies needed for sanitizers to link into executables and
 # shared_libraries. Unconditionally depend upon this target as it is empty if
@@ skipping 10 matching lines @@
     ]
     deps = [
       ":options_sources",
     ]
 
     if (use_prebuilt_instrumented_libraries) {
       deps += [ "//third_party/instrumented_libraries: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") {
   visibility = [
     ":deps",
     "//:gn_visibility",
   ]
   sources = [
     "//build/sanitizers/sanitizer_options.cc",
   ]
@@ skipping 241 matching lines @@
     if (use_custom_libcxx) {
       prefix = "//buildtools/third_party"
       include = "trunk/include"
       cflags_cc += [
         "-nostdinc++",
         "-isystem" + rebase_path("$prefix/libc++/$include", root_build_dir),
         "-isystem" + rebase_path("$prefix/libc++abi/$include", root_build_dir),
       ]
     }
   }
-
-  if (is_mac && is_asan) {
-    libs = [ "clang_rt.asan_osx_dynamic" ]
-  }
 }
 
 config("default_sanitizer_coverage_flags") {
   cflags = []
 
   if (use_sanitizer_coverage) {
     # FIXME: make this configurable.
     cflags += [
       "-fsanitize-coverage=edge,indirect-calls,8bit-counters",
       "-mllvm",
       "-sanitizer-coverage-prune-blocks=1",
     ]
   }
 }
-
-# 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}}",
-    ]
-  }
-}