Fix background compilation: handle compilation abort during parsing.

runtime/vm/object.cc

 // Copyright (c) 2012, 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 "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 2964 matching lines @@
   return result.raw();
 }
 
 
 // Ensure that top level parsing of the class has been done.
 RawError* Class::EnsureIsFinalized(Thread* thread) const {
   // Finalized classes have already been parsed.
   if (is_finalized()) {
     return Error::null();
   }
+  if (Compiler::IsBackgroundCompilation()) {
+    Compiler::AbortBackgroundCompilation(Thread::kNoDeoptId);
+  }
   ASSERT(thread->IsMutatorThread());
   ASSERT(thread != NULL);
   const Error& error = Error::Handle(
       thread->zone(), Compiler::CompileClass(*this));
   if (!error.IsNull()) {
     ASSERT(thread == Thread::Current());
     if (thread->long_jump_base() != NULL) {
       Report::LongJump(error);
       UNREACHABLE();
     }
@@ skipping 18729 matching lines @@
   return UserTag::null();
 }
 
 
 const char* UserTag::ToCString() const {
   const String& tag_label = String::Handle(label());
   return tag_label.ToCString();
 }
 
 }  // namespace dart