gen_snapshot now generates two snapshot buffers, one for the vm isolate

sky/engine/bindings/BUILD.gn

 # Copyright 2015 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("//sky/engine/bindings/bindings.gni")
 import("//sky/engine/core/core.gni")
 
 source_set("bindings") {
   sources = [
     "builtin.cc",
@@ skipping 43 matching lines @@
   ]
   inputs = [
     "//dart/runtime/tools/create_snapshot_bin.py",
     "//sky/engine/bindings/builtin.dart",
     "//mojo/public/dart/internal.dart",
     "//mojo/public/dart/src/handle_watcher.dart",
     "//mojo/public/dart/src/natives.dart",
     "//mojo/public/dart/src/timer_queue.dart",
     "snapshot.dart",
   ]
-  output = "$target_gen_dir/snapshot_gen.bin"
+  vm_isolate_snapshot = "$target_gen_dir/vm_isolate_snapshot.bin"
+  isolate_snapshot = "$target_gen_dir/isolate_snapshot.bin"
   outputs = [
-    output,
+    vm_isolate_snapshot,
+    isolate_snapshot,
   ]
 
   builtin_path = rebase_path("//sky/engine/bindings/builtin.dart")
   dart_sky_path = rebase_path("$bindings_output_dir/dart_sky.dart")
   internal_path = rebase_path("//mojo/public/dart/internal.dart")
 
   gen_snapshot_dir =
       get_label_info("//dart/runtime/bin:gen_snapshot($host_toolchain)",
                      "root_out_dir")
   script = "//dart/runtime/tools/create_snapshot_bin.py"
 
   args = [
     "--executable",
     rebase_path("$gen_snapshot_dir/gen_snapshot"),
     "--package_root",
     rebase_path("$root_gen_dir"),
     "--script",
     rebase_path("snapshot.dart"),
+    "--vm_output_bin",
+    rebase_path(vm_isolate_snapshot, root_build_dir),
     "--output_bin",
-    rebase_path(output, root_build_dir),
+    rebase_path(isolate_snapshot, root_build_dir),
     "--target_os",
     os,
     "--url_mapping=dart:sky,$dart_sky_path",
     "--url_mapping=dart:mojo.internal,$internal_path",
     "--url_mapping=dart:sky_builtin,$builtin_path",
   ]
 }
 
 action("generate_snapshot_file") {
   deps = [
     ":generate_snapshot_bin",
   ]
   inputs = [
     "//dart/runtime/tools/create_snapshot_file.py",
     "snapshot.cc.tmpl",
-    "$target_gen_dir/snapshot_gen.bin",
+    "$target_gen_dir/vm_isolate_snapshot.bin",
+    "$target_gen_dir/isolate_snapshot.bin",
   ]
   output = "$target_gen_dir/snapshot.cc"
   outputs = [
     output,
   ]
 
   script = "//dart/runtime/tools/create_snapshot_file.py"
   args = [
+    "--vm_input_bin",
+    rebase_path("$target_gen_dir/vm_isolate_snapshot.bin"),
     "--input_bin",
-    rebase_path("$target_gen_dir/snapshot_gen.bin"),
+    rebase_path("$target_gen_dir/isolate_snapshot.bin"),
     "--input_cc",
     rebase_path("snapshot.cc.tmpl"),
     "--output",
     rebase_path(output),
   ]
 }
 
 source_set("snapshot_cc") {
   sources = [
     "$target_gen_dir/snapshot.cc",
@@ skipping 251 matching lines @@
   ]
 
   include_dirs = [
     "..",
     "$root_build_dir",
   ]
 
   sources = get_target_outputs(":compile_idls")
   sources += get_target_outputs(":generate_dart_globals")
 }