Introduce a CompilerDispatcherTracer and track how long jobs take

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

Index: src/compiler-dispatcher/compiler-dispatcher-job.h
diff --git a/src/compiler-dispatcher/compiler-dispatcher-job.h b/src/compiler-dispatcher/compiler-dispatcher-job.h
index f3aaf939e0d4bc592e6879eb8ddfed5486785439..f5bb8f555a333901877df2867f05b81d2a082d82 100644
--- a/src/compiler-dispatcher/compiler-dispatcher-job.h
+++ b/src/compiler-dispatcher/compiler-dispatcher-job.h
@@ -14,6 +14,7 @@
 namespace v8 {
 namespace internal {
 
+class CompilerDispatcherTracer;
 class CompilationInfo;
 class CompilationJob;
 class Isolate;
@@ -81,6 +82,7 @@ class CompilerDispatcherJob {
 
   CompileJobStatus status_ = CompileJobStatus::kInitial;
   Isolate* isolate_;
+  CompilerDispatcherTracer* tracer_;
   Handle<SharedFunctionInfo> shared_;  // Global handle.
   Handle<String> source_;        // Global handle.
   size_t max_stack_size_;