Investigate & fix issues around usage_count and deoptimization_count

runtime/vm/object.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 1336 matching lines @@
                                      intptr_t token_pos);
 
   // Patch the signature function of a signature class allocated without it.
   void PatchSignatureFunction(const Function& signature_function) const;
 
   // Register code that has used CHA for optimization.
   // TODO(srdjan): Also register kind of CHA optimization (e.g.: leaf class,
   // leaf method, ...).
   void RegisterCHACode(const Code& code);
 
-  void DisableCHAOptimizedCode();
+  void DisableCHAOptimizedCode(const Class& subclass);
 
   RawArray* cha_codes() const { return raw_ptr()->cha_codes_; }
   void set_cha_codes(const Array& value) const;
 
   bool TraceAllocation(Isolate* isolate) const;
   void SetTraceAllocation(bool trace_allocation) const;
 
  private:
   enum MemberKind {
     kAny = 0,
@@ skipping 6864 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_