Remember all deopt reasons in ic_data, not just the last one.

runtime/vm/code_patcher_x64.cc

 // 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.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/code_patcher.h"
 #include "vm/cpu.h"
@@ skipping 55 matching lines @@
 };
 
 
 class InstanceCall : public UnoptimizedCall {
  public:
   InstanceCall(uword return_address, const Code& code)
       : UnoptimizedCall(return_address, code) {
 #if defined(DEBUG)
     ICData& test_ic_data = ICData::Handle();
     test_ic_data ^= ic_data();
-    ASSERT(test_ic_data.num_args_tested() > 0);
+    ASSERT(test_ic_data.NumArgsTested() > 0);
 #endif  // DEBUG
   }
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(InstanceCall);
 };
 
 
 class UnoptimizedStaticCall : public UnoptimizedCall {
  public:
   UnoptimizedStaticCall(uword return_address, const Code& code)
       : UnoptimizedCall(return_address, code) {
 #if defined(DEBUG)
     ICData& test_ic_data = ICData::Handle();
     test_ic_data ^= ic_data();
-    ASSERT(test_ic_data.num_args_tested() >= 0);
+    ASSERT(test_ic_data.NumArgsTested() >= 0);
 #endif  // DEBUG
   }
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(UnoptimizedStaticCall);
 };
 
 
 // The expected pattern of a dart static call:
 //  00 mov R10, arguments_descriptor_array (10 bytes) (optional in polym. calls)
@@ skipping 226 matching lines @@
 
 RawObject* CodePatcher::GetEdgeCounterAt(uword pc, const Code& code) {
   ASSERT(code.ContainsInstructionAt(pc));
   EdgeCounter counter(pc, code);
   return counter.edge_counter();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64