Add a flag for printf debugging the compiler dispatcher

src/compiler-dispatcher/compiler-dispatcher-job.h

 // 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.
 
 #ifndef V8_COMPILER_DISPATCHER_COMPILER_DISPATCHER_JOB_H_
 #define V8_COMPILER_DISPATCHER_COMPILER_DISPATCHER_JOB_H_
 
 #include <memory>
 
 #include "src/base/macros.h"
@@ skipping 68 matching lines @@
   // Transition from kCompiled to kDone (or kFailed). Returns false when
   // transitioning to kFailed. In that case, an exception is pending.
   bool FinalizeCompilingOnMainThread();
 
   // Transition from any state to kInitial and free all resources.
   void ResetOnMainThread();
 
   // Estimate how long the next step will take using the tracer.
   double EstimateRuntimeOfNextStepInMs() const;
 
+  // Even though the name does not imply this, ShortPrint() must only be invoked
+  // on the main thread.
+  void ShortPrint();
+
  private:
   FRIEND_TEST(CompilerDispatcherJobTest, ScopeChain);
 
   CompileJobStatus status_ = CompileJobStatus::kInitial;
   Isolate* isolate_;
   CompilerDispatcherTracer* tracer_;
   Handle<SharedFunctionInfo> shared_;  // Global handle.
   Handle<String> source_;        // Global handle.
   size_t max_stack_size_;
 
   // Members required for parsing.
   std::unique_ptr<UnicodeCache> unicode_cache_;
   std::unique_ptr<Zone> zone_;
   std::unique_ptr<Utf16CharacterStream> character_stream_;
   std::unique_ptr<ParseInfo> parse_info_;
   std::unique_ptr<Parser> parser_;
   std::unique_ptr<DeferredHandles> handles_from_parsing_;
 
   // Members required for compiling.
   std::unique_ptr<CompilationInfo> compile_info_;
   std::unique_ptr<CompilationJob> compile_job_;
 
   bool can_parse_on_background_thread_;
   bool can_compile_on_background_thread_;
 
+  bool trace_compiler_dispatcher_jobs_;
+
   DISALLOW_COPY_AND_ASSIGN(CompilerDispatcherJob);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_DISPATCHER_COMPILER_DISPATCHER_JOB_H_