Moves BUILD.gn config from root to runtime.

runtime/vm/BUILD.gn

 # Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 config("libdart_vm_config") {
   libs = [
     "pthread",
     "rt",
     "dl",
   ]
 }
 
 
 static_library("libdart_platform") {
-  configs += ["../..:dart_config"]
+  configs += ["..:dart_config"]
   public_configs = [":libdart_vm_config"]
 
   platform_headers_gypi =
       exec_script("../../tools/gypi_to_gn.py",
                   [rebase_path("../platform/platform_headers.gypi")],
                   "scope",
                   ["../platform/platform_headers.gypi"])
   platform_headers =
       rebase_path(platform_headers_gypi.sources, ".", "../platform")
 
   platform_sources_gypi =
       exec_script("../../tools/gypi_to_gn.py",
                   [rebase_path("../platform/platform_sources.gypi")],
                   "scope",
                   ["../platform/platform_sources.gypi"])
   platform_sources =
       rebase_path(platform_sources_gypi.sources, ".", "../platform")
 
   sources = platform_headers + platform_sources
   include_dirs = [
     "..",
   ]
 }
 
 
 static_library("libdart_vm") {
-  configs += ["../..:dart_config"]
+  configs += ["..:dart_config"]
   public_configs = [":libdart_vm_config"]
   deps = [ ":generate_service_cc_file", ]
 
   vm_sources_list = exec_script("../../tools/gypi_to_gn.py",
                                 [rebase_path("vm_sources.gypi")],
                                 "scope",
                                 ["vm_sources.gypi"])
 
   set_sources_assignment_filter(["*_test.cc", "*_test.h"])
   sources = vm_sources_list.sources
@@ skipping 83 matching lines @@
                     "scope",
                     ["../lib/${filename}_sources.gypi"])
     libsources += rebase_path(lib_sources_gypi.sources, ".", "../lib")
     liboutputs += ["$target_gen_dir/${filename}_gen.cc",
                    "$target_gen_dir/${filename}_patch_gen.cc"]
     libdeps += [":generate_${filename}_cc_file",
                 ":generate_${filename}_patch_cc_file"]
   }
 
   static_library("libdart_lib_withcore") {
-    configs += ["../..:dart_config"]
+    configs += ["..:dart_config"]
     deps = libdeps
     sources = libsources + ["bootstrap.cc"] + liboutputs
     include_dirs = [
       "..",
     ]
   }
   static_library("libdart_lib") {
-    configs += ["../..:dart_config"]
+    configs += ["..:dart_config"]
     sources = libsources + [ "bootstrap_nocore.cc", ]
     include_dirs = [
       "..",
     ]
   }
 }
 
 
 generate_core_libraries("core_libraries") {
   sources = [
@@ skipping 27 matching lines @@
   output = "$target_gen_dir/service_gen.cc"
   outputs = [ output, ]
 
   args = [
     "--output", rebase_path(output, root_build_dir),
     "--outer_namespace", "dart",
     "--table_name", "service",
     "--root_prefix", rebase_path("service/", root_build_dir)] +
     rebase_path(sources, root_build_dir)
 }