Refactor the functions related to collecting code statistics to a new class.

src/heap/code-stats.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.
+
+#include "src/assembler.h"
+#include "src/heap/spaces.h"
+#include "src/isolate.h"
+#include "src/objects.h"
+
+namespace v8 {
+namespace internal {
+
+class CodeStatistics {
+ public:
+  // Collect statistics related to code size.
+  static void CollectCodeStatistics(PagedSpace* space, Isolate* isolate);
+
+  // Collect statistics related to code size from large object space.
+  static void CollectCodeStatistics(LargeObjectSpace* space, Isolate* isolate);
+
+  // Reset code size related statistics
+  static void ResetCodeAndMetadataStatistics(Isolate* isolate);
+
+#ifdef DEBUG
+  // Report statistics about code kind, code+metadata and code comments.
+  static void ReportCodeStatistics(Isolate* isolate);
+#endif
+
+ private:
+  static void RecordCodeAndMetadataStatistics(HeapObject* object,
+                                              Isolate* isolate);
+
+#ifdef DEBUG
+  static void CollectCommentStatistics(Isolate* isolate, RelocIterator* it);
+  static void CollectCodeCommentStatistics(HeapObject* obj, Isolate* isolate);
+  static void EnterComment(Isolate* isolate, const char* comment, int delta);
+  static void ResetCodeStatistics(Isolate* isolate);
+#endif
+};
+
+}  // namespace internal
+}  // namespace v8