[Compiler] Ensure we enter the correct context for compiler-dispatcher jobs.

src/compiler-dispatcher/compiler-dispatcher.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler-dispatcher/compiler-dispatcher.h"
 
 #include "include/v8-platform.h"
 #include "include/v8.h"
 #include "src/base/platform/time.h"
 #include "src/cancelable-task.h"
 #include "src/compilation-info.h"
 #include "src/compiler-dispatcher/compiler-dispatcher-job.h"
 #include "src/compiler-dispatcher/compiler-dispatcher-tracer.h"
 #include "src/flags.h"
 #include "src/objects-inl.h"
 
 namespace v8 {
 namespace internal {
 
 namespace {
 
 enum class ExceptionHandling { kSwallow, kThrow };
 
 bool DoNextStepOnMainThread(Isolate* isolate, CompilerDispatcherJob* job,
                             ExceptionHandling exception_handling) {
   DCHECK(ThreadId::Current().Equals(isolate->thread_id()));
+
+  // Ensure we are in the correct context for the job.
+  SaveContext save(isolate);
+  isolate->set_context(job->context());
+
   switch (job->status()) {
     case CompileJobStatus::kInitial:
       job->PrepareToParseOnMainThread();
       break;
 
     case CompileJobStatus::kReadyToParse:
       job->Parse();
       break;
 
     case CompileJobStatus::kParsed:
@@ skipping 665 matching lines @@
       lock.reset();
       DoNextStepOnMainThread(isolate_, job->second.get(),
                              ExceptionHandling::kSwallow);
     }
   }
   if (jobs_.size() > too_long_jobs) ScheduleIdleTaskIfNeeded();
 }
 
 }  // namespace internal
 }  // namespace v8