[Counters] Add HistorgramTimers for optimized compile.

Will be used for UMA to track time spent optimizing code in the wild.

Change-Id: Ibc01540552eac4cb9224f1cb6cc11a55aae5834d
Reviewed-on: https://chromium-review.googlesource.com/444345Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43374}

src/compiler-dispatcher/optimizing-compile-dispatcher.cc

@@ -50,6 +50,8 @@ class OptimizingCompileDispatcher::CompileTask : public v8::Task {
     DisallowHandleDereference no_deref;
 
     {
+      HistogramTimerScope histogram_timer(
+          isolate_->counters()->compile_optimized_background_thread());
       TimerEventScope<TimerEventRecompileConcurrent> timer(isolate_);
 
       TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),

src/compiler.cc

@@ -874,6 +874,8 @@ MaybeHandle<Code> GetOptimizedCode(Handle<JSFunction> function,
     return MaybeHandle<Code>();
   }
 
+  HistogramTimerScope timer(
+      isolate->counters()->compile_optimized_main_thread());
   TimerEventScope<TimerEventOptimizeCode> optimize_code_timer(isolate);
   RuntimeCallTimerScope runtimeTimer(isolate, &RuntimeCallStats::OptimizeCode);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.OptimizeCode");
@@ -928,6 +930,8 @@ CompilationJob::Status FinalizeOptimizedCompilationJob(CompilationJob* job) {
   CompilationInfo* info = job->info();
   Isolate* isolate = info->isolate();
 
+  HistogramTimerScope histogram_timer(
+      isolate->counters()->compile_optimized_main_thread());
   TimerEventScope<TimerEventRecompileSynchronous> timer(info->isolate());
   RuntimeCallTimerScope runtimeTimer(isolate,
                                      &RuntimeCallStats::RecompileSynchronous);

src/counters.h

@@ -969,6 +969,11 @@ class RuntimeCallTimerScope {
   HT(compile_serialize, V8.CompileSerializeMicroSeconds, 100000, MICROSECOND)  \
   HT(compile_deserialize, V8.CompileDeserializeMicroSeconds, 1000000,          \
      MICROSECOND)                                                              \
+  /* Optimized compile times. */                                               \
+  HT(compile_optimized_main_thread, V8.CompileOptimizedMainThreadMicroSeconds, \
+     1000000, MICROSECOND)                                                     \
+  HT(compile_optimized_background_thread,                                      \
+     V8.CompileOptimizeBackgroundThreadMicroSeconds, 1000000, MICROSECOND)     \
   /* Total compilation time incl. caching/parsing */                           \
   HT(compile_script, V8.CompileScriptMicroSeconds, 1000000, MICROSECOND)       \
   /* Total JavaScript execution time (including callbacks and runtime calls */ \