Exclude Observatory assets from PRODUCT build dart, dart_precompiled_runtime

runtime/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.
 
 import("runtime_args.gni")
 
-declare_args() {
-  # Instead of using is_debug, we introduce a different flag for specifying a
-  # Debug build of Dart so that clients can still use a Release build of Dart
-  # while themselves doing a Debug build.
-  dart_debug = false
-
-  # Set the runtime mode. This affects how the runtime is built and what
-  # features it has. Valid values are:
-  # 'develop' (the default) - VM is built to run as a JIT with all development
-  # features enabled.
-  # 'profile' - The VM is built to run with AOT compiled code with only the
-  # CPU profiling features enabled.
-  # 'release' - The VM is built to run with AOT compiled code with no developer
-  # features enabled.
-  #
-  # These settings are only used for Flutter, at the moment. A standalone build
-  # of the Dart VM should leave this set to "develop", and should set
-  # 'is_debug', 'is_release', or 'is_product'.
-  dart_runtime_mode = "develop"
-
-  # Explicitly set the target architecture in case of precompilation. Leaving
-  # this unspecified results in automatic target architecture detection.
-  # Available options are: arm, arm64, x64, and ia32
-  dart_target_arch = ""
-
-  # The optimization level to use for debug builds.
-  dart_debug_optimization_level = "2"
-}
-
 config("dart_public_config") {
   include_dirs = [ "." ]
 }
 
 # Adds PRODUCT define if Flutter has specified "release" for dart_runtime_mode
 config("dart_maybe_product_config") {
   defines = []
 
   if (dart_runtime_mode != "develop" && dart_runtime_mode != "profile" &&
       dart_runtime_mode != "release") {
@@ skipping 232 matching lines @@
 
   script = "../tools/make_version.py"
   args = [
     "--quiet",
     "--output",
     rebase_path(output, root_build_dir),
     "--input",
     rebase_path("vm/version_in.cc", root_build_dir),
   ]
 }