Revert of Revert of Revert of Add d8 target to the GN build.

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.
 
 # Because standalone V8 builds are not supported, assume this is part of a
 # Chromium build.
 import("//build/module_args/v8.gni")
 
 # TODO(jochen): These will need to be user-settable to support standalone V8
 # builds.
@@ skipping 173 matching lines @@
 
   if (v8_use_external_startup_data) {
     outputs += [ "$target_gen_dir/libraries.bin" ]
     args += [
       "--startup_blob",
       rebase_path("$target_gen_dir/libraries.bin", root_build_dir),
     ]
   }
 }
 
-action("d8_js2c") {
-  visibility = [ ":*" ]  # Only targets in this file can depend on this.
-
-  script = "tools/js2c.py"
-
-  inputs = [
-    "src/d8.js",
-    "src/macros.py",
-  ]
-  outputs = [
-    "$target_gen_dir/d8-js.cc",
-  ]
-
-  args = rebase_path(outputs, root_build_dir) + [ "D8" ] +
-         rebase_path(inputs, root_build_dir)
-}
-
 action("js2c_experimental") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
 
   script = "tools/js2c.py"
 
   # The script depends on this other script, this rule causes a rebuild if it
   # changes.
   source_prereqs = [ "tools/jsmin.py" ]
 
   sources = [
@@ skipping 1193 matching lines @@
       ":toolchain",
     ]
 
     deps = [
       ":v8_base",
       ":v8_libplatform",
       ":v8_nosnapshot",
       "//build/config/sanitizers:deps",
     ]
   }
-
-  executable("d8") {
-    sources = [
-      "src/d8.cc",
-    ]
-    deps = [
-      ":d8_js2c",
-      ":v8",
-      ":v8_libplatform",
-    ]
-
-    configs += [
-      ":internal_config",
-      ":features",
-      ":toolchain",
-    ]
-
-    # TODO(GYP): Build option for readline support.
-
-    if (is_posix) {
-      sources += [ "src/d8-posix.cc" ]
-    } else if (is_win) {
-      sources += [ "src/d8-windows.cc" ]
-    }
-
-    if (component_mode != "shared_library") {
-      sources += [
-        "src/d8-debug.cc",
-        "$target_gen_dir/d8-js.cc",
-      ]
-    }
-    if (v8_enable_i18n_support) {
-      deps += [ "//third_party/icu" ]
-    }
-
-    # TODO(GYP) v8_enable_vtunejit support in d8.
-  }
 }
 
 ###############################################################################
 # Public targets
 #
 
 if (component_mode == "shared_library") {
   component("v8") {
     sources = [
       "src/v8dll-main.cc",
@@ skipping 48 matching lines @@
       assert(!v8_use_external_startup_data)
       deps = [
         ":v8_base",
         ":v8_nosnapshot",
       ]
     }
 
     direct_dependent_configs = [ ":external_config" ]
   }
 }