[heap] Tracer: Eliminate prefix for external callbacks

The distinction didn't provide any benefits.

BUG=chromium:651354

Review-Url: https://codereview.chromium.org/2492433002
Cr-Commit-Position: refs/heads/master@{#40853}

src/heap/gc-tracer.cc

@@ -447,8 +447,8 @@ void GCTracer::PrintNVP() const {
           "code=%.2f "
           "semispace=%.2f "
           "object_groups=%.2f "
-          "external_prologue=%.2f "
-          "external_epilogue=%.2f "
+          "external.prologue=%.2f "
+          "external.epilogue=%.2f "
           "external_weak_global_handles=%.2f "
           "steps_count=%d "
           "steps_took=%.1f "
@@ -484,8 +484,8 @@ void GCTracer::PrintNVP() const {
           current_.scopes[Scope::SCAVENGER_CODE_FLUSH_CANDIDATES],
           current_.scopes[Scope::SCAVENGER_SEMISPACE],
           current_.scopes[Scope::SCAVENGER_OBJECT_GROUPS],
-          current_.scopes[Scope::SCAVENGER_EXTERNAL_PROLOGUE],
-          current_.scopes[Scope::SCAVENGER_EXTERNAL_EPILOGUE],
+          current_.scopes[Scope::EXTERNAL_PROLOGUE],
+          current_.scopes[Scope::EXTERNAL_EPILOGUE],
           current_.scopes[Scope::EXTERNAL_WEAK_GLOBAL_HANDLES],
           current_.incremental_marking_scopes[GCTracer::Scope::MC_INCREMENTAL]
               .steps,
@@ -529,8 +529,8 @@ void GCTracer::PrintNVP() const {
           "evacuate.update_pointers.to_evacuated=%.1f "
           "evacuate.update_pointers.to_new=%.1f "
           "evacuate.update_pointers.weak=%.1f "
-          "external.mc_prologue=%.1f "
-          "external.mc_epilogue=%.1f "
+          "external.prologue=%.1f "
+          "external.epilogue=%.1f "
           "external.weak_global_handles=%.1f "
           "finish=%.1f "
           "mark=%.1f "
@@ -612,8 +612,8 @@ void GCTracer::PrintNVP() const {
           current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS_TO_EVACUATED],
           current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS_TO_NEW],
           current_.scopes[Scope::MC_EVACUATE_UPDATE_POINTERS_WEAK],
-          current_.scopes[Scope::MC_EXTERNAL_PROLOGUE],
-          current_.scopes[Scope::MC_EXTERNAL_EPILOGUE],
+          current_.scopes[Scope::EXTERNAL_PROLOGUE],
+          current_.scopes[Scope::EXTERNAL_EPILOGUE],
           current_.scopes[Scope::EXTERNAL_WEAK_GLOBAL_HANDLES],
           current_.scopes[Scope::MC_FINISH], current_.scopes[Scope::MC_MARK],
           current_.scopes[Scope::MC_MARK_FINISH_INCREMENTAL],

src/heap/gc-tracer.h

@@ -37,6 +37,8 @@ enum ScavengeSpeedMode { kForAllObjects, kForSurvivedObjects };
 
 #define TRACER_SCOPES(F)                      \
   INCREMENTAL_SCOPES(F)                       \
+  F(EXTERNAL_EPILOGUE)                        \
+  F(EXTERNAL_PROLOGUE)                        \
   F(EXTERNAL_WEAK_GLOBAL_HANDLES)             \
   F(MC_CLEAR)                                 \
   F(MC_CLEAR_CODE_FLUSH)                      \
@@ -58,8 +60,6 @@ enum ScavengeSpeedMode { kForAllObjects, kForSurvivedObjects };
   F(MC_EVACUATE_UPDATE_POINTERS_TO_EVACUATED) \
   F(MC_EVACUATE_UPDATE_POINTERS_TO_NEW)       \
   F(MC_EVACUATE_UPDATE_POINTERS_WEAK)         \
-  F(MC_EXTERNAL_EPILOGUE)                     \
-  F(MC_EXTERNAL_PROLOGUE)                     \
   F(MC_FINISH)                                \
   F(MC_MARK)                                  \
   F(MC_MARK_FINISH_INCREMENTAL)               \
@@ -80,8 +80,6 @@ enum ScavengeSpeedMode { kForAllObjects, kForSurvivedObjects };
   F(MC_SWEEP_MAP)                             \
   F(MC_SWEEP_OLD)                             \
   F(SCAVENGER_CODE_FLUSH_CANDIDATES)          \
-  F(SCAVENGER_EXTERNAL_EPILOGUE)              \
-  F(SCAVENGER_EXTERNAL_PROLOGUE)              \
   F(SCAVENGER_OBJECT_GROUPS)                  \
   F(SCAVENGER_OLD_TO_NEW_POINTERS)            \
   F(SCAVENGER_ROOTS)                          \
@@ -364,12 +362,10 @@ class V8_EXPORT_PRIVATE GCTracer {
 
   double TotalExternalTime() const {
     return current_.scopes[Scope::EXTERNAL_WEAK_GLOBAL_HANDLES] +
-           current_.scopes[Scope::MC_EXTERNAL_EPILOGUE] +
-           current_.scopes[Scope::MC_EXTERNAL_PROLOGUE] +
+           current_.scopes[Scope::EXTERNAL_EPILOGUE] +
+           current_.scopes[Scope::EXTERNAL_PROLOGUE] +
            current_.scopes[Scope::MC_INCREMENTAL_EXTERNAL_EPILOGUE] +
-           current_.scopes[Scope::MC_INCREMENTAL_EXTERNAL_PROLOGUE] +
-           current_.scopes[Scope::SCAVENGER_EXTERNAL_EPILOGUE] +
-           current_.scopes[Scope::SCAVENGER_EXTERNAL_PROLOGUE];
+           current_.scopes[Scope::MC_INCREMENTAL_EXTERNAL_PROLOGUE];
   }
 
   // Pointer to the heap that owns this tracer.

src/heap/heap.cc

@@ -1292,9 +1292,7 @@ bool Heap::PerformGarbageCollection(
     GCCallbacksScope scope(this);
     if (scope.CheckReenter()) {
       AllowHeapAllocation allow_allocation;
-      TRACE_GC(tracer(), collector == MARK_COMPACTOR
-                             ? GCTracer::Scope::MC_EXTERNAL_PROLOGUE
-                             : GCTracer::Scope::SCAVENGER_EXTERNAL_PROLOGUE);
+      TRACE_GC(tracer(), GCTracer::Scope::EXTERNAL_PROLOGUE);
       VMState<EXTERNAL> state(isolate_);
       HandleScope handle_scope(isolate_);
       CallGCPrologueCallbacks(gc_type, kNoGCCallbackFlags);
@@ -1363,9 +1361,7 @@ bool Heap::PerformGarbageCollection(
     GCCallbacksScope scope(this);
     if (scope.CheckReenter()) {
       AllowHeapAllocation allow_allocation;
-      TRACE_GC(tracer(), collector == MARK_COMPACTOR
-                             ? GCTracer::Scope::MC_EXTERNAL_EPILOGUE
-                             : GCTracer::Scope::SCAVENGER_EXTERNAL_EPILOGUE);
+      TRACE_GC(tracer(), GCTracer::Scope::EXTERNAL_EPILOGUE);
       VMState<EXTERNAL> state(isolate_);
       HandleScope handle_scope(isolate_);
       CallGCEpilogueCallbacks(gc_type, gc_callback_flags);