Wire up the interpreter on iOS devices. (#2648)

DEPS

@@ -25,7 +25,7 @@ vars = {
 
   # Note: When updating the Dart revision, ensure that all entries that are
   # dependencies of dart are also updated
-  'dart_revision': '14ec00f86bbc893f1c731ea36afb1b98d8cd77cc',
+  'dart_revision': 'e4db01fdd43f019988a901eb51c72790652760a4',
   'dart_boringssl_revision': 'daeafc22c66ad48f6b32fc8d3362eb9ba31b774e',
   'dart_observatory_packages_revision': 'cf90eb9077177d3d6b3fd5e8289477c2385c026a',
   'dart_root_certificates_revision': 'aed07942ce98507d2be28cbd29e879525410c7fc',

engine/src/flutter/sky/tools/gn

@@ -50,6 +50,11 @@ def to_gn_args(args):
     gn_args['is_debug'] = args.debug
     gn_args['is_clang'] = args.clang and args.target_os not in ['android']
 
+
+    ios_target_cpu = 'arm64'
+    if args.ios_force_armv7:
+      ios_target_cpu = 'arm'
+
     if args.target_os == 'android':
         gn_args['target_os'] = 'android'
         aot = not args.develop
@@ -88,6 +93,8 @@ def to_gn_args(args):
     else:
         gn_args['dart_runtime_mode'] = 'develop'
 
+    gn_args['dart_experimental_interpreter'] = args.experimental_interpreter
+
     gn_args['flutter_product_mode'] = (gn_args['dart_runtime_mode'] == 'release')
 
     if args.target_sysroot:
@@ -126,6 +133,7 @@ def parse_args(args):
   # Adding it now unblocks bot/tool work.
   parser.add_argument('--develop', default=True, action='store_true')
   parser.add_argument('--deploy', default=False, dest='develop', action='store_false')
+  parser.add_argument('--experimental-interpreter', default=False, dest='experimental_interpreter', action='store_true')
 
   parser.add_argument('--target-os', type=str, choices=['android', 'ios'])
   parser.add_argument('--android', dest='target_os', action='store_const', const='android')

engine/src/flutter/sky/tools/sky_snapshot/vm.cc

@@ -17,6 +17,11 @@ static const char* kDartArgs[] = {
     "--enable_mirrors=false",
     "--load_deferred_eagerly=true",
     "--conditional_directives",
+    // TODO(chinmaygarde): The experimental interpreter for iOS device targets
+    // does not support all these flags. The build process uses its own version
+    // of this snapshotter. Till support for all these flags is added, make
+    // sure the snapshotter does not error out on unrecognized flags.
+    "--ignore-unrecognized-flags",
 };
 
 void InitDartVM() {