GN: Build the SDK with app snapshots instead of script snapshots.

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2013, 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.
 
 #include "include/dart_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 
 #include "platform/assert.h"
 #include "lib/stacktrace.h"
@@ skipping 95 matching lines @@
 class FunctionVisitor : public ObjectVisitor {
  public:
   explicit FunctionVisitor(Thread* thread) :
       classHandle_(Class::Handle(thread->zone())),
       funcHandle_(Function::Handle(thread->zone())),
       typeHandle_(AbstractType::Handle(thread->zone())) {}
 
   void VisitObject(RawObject* obj) {
     if (obj->IsFunction()) {
       funcHandle_ ^= obj;
+      if (funcHandle_.IsSignatureFunction()) {
+        // TODO(27606): Remove signature function case.
+        return;
+      }
+
       classHandle_ ^= funcHandle_.Owner();
       // Verify that the result type of a function is canonical or a
       // TypeParameter.
       typeHandle_ ^= funcHandle_.result_type();
       ASSERT(typeHandle_.IsMalformed() ||
              !typeHandle_.IsResolved() ||
              typeHandle_.IsTypeParameter() ||
              typeHandle_.IsCanonical());
       // Verify that the types in the function signature are all canonical or
       // a TypeParameter.
@@ skipping 6513 matching lines @@
 
 DART_EXPORT bool Dart_IsPrecompiledRuntime() {
 #if defined(DART_PRECOMPILED_RUNTIME)
   return true;
 #else
   return false;
 #endif
 }
 
 }  // namespace dart