[serializer] tweak startup serializer for warming up.

Code that we want to keep after warming up may have context-dependent
inline caches. Clear these to avoid running into IC misses after
deserialization.

R=vogelheim@chromium.org
BUG=v8:4836
LOG=N

Review URL: https://codereview.chromium.org/1811263002

Cr-Commit-Position: refs/heads/master@{#34945}

src/api.cc

@@ -501,13 +501,17 @@ StartupData V8::WarmUpSnapshotDataBlob(StartupData cold_snapshot_blob,
     Isolate::Scope isolate_scope(isolate);
     i::Snapshot::Initialize(internal_isolate);
     Persistent<Context> context;
+    bool success;
     {
       HandleScope handle_scope(isolate);
-      Local<Context> warmup_context = Context::New(isolate);
-      if (RunExtraCode(isolate, warmup_context, warmup_source, "<warm-up>")) {
-        Local<Context> fresh_context = Context::New(isolate);
-        context.Reset(isolate, fresh_context);
+      Local<Context> new_context = Context::New(isolate);
+      success = RunExtraCode(isolate, new_context, warmup_source, "<warm-up>");
     }
+    if (success) {
+      HandleScope handle_scope(isolate);
+      isolate->ContextDisposedNotification(false);
+      Local<Context> new_context = Context::New(isolate);
+      context.Reset(isolate, new_context);
     }
 
     i::Snapshot::Metadata metadata;

src/snapshot/startup-serializer.cc

@@ -27,19 +27,27 @@ void StartupSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
                                         WhereToPoint where_to_point, int skip) {
   DCHECK(!obj->IsJSFunction());
 
+  if (function_code_handling_ == CLEAR_FUNCTION_CODE) {
     if (obj->IsCode()) {
       Code* code = Code::cast(obj);
       // If the function code is compiled (either as native code or bytecode),
       // replace it with lazy-compile builtin. Only exception is when we are
       // serializing the canonical interpreter-entry-trampoline builtin.
-    if (function_code_handling_ == CLEAR_FUNCTION_CODE &&
-        (code->kind() == Code::FUNCTION ||
-         (!serializing_builtins_ && code->is_interpreter_entry_trampoline()))) {
+      if (code->kind() == Code::FUNCTION ||
+          (!serializing_builtins_ && code->is_interpreter_entry_trampoline())) {
         obj = isolate()->builtins()->builtin(Builtins::kCompileLazy);
       }
     } else if (obj->IsBytecodeArray()) {
       obj = isolate()->heap()->undefined_value();
     }
+  } else if (obj->IsCode()) {
+    DCHECK_EQ(KEEP_FUNCTION_CODE, function_code_handling_);
+    Code* code = Code::cast(obj);
+    if (code->kind() == Code::FUNCTION) {
+      code->ClearInlineCaches();
+      code->set_profiler_ticks(0);
+    }
+  }
 
   int root_index = root_index_map_.Lookup(obj);
   // We can only encode roots as such if it has already been serialized.