Remove isolate parameter when allocating handles

runtime/vm/coverage.h

 // Copyright (c) 2013, 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_COVERAGE_H_
 #define VM_COVERAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/flags.h"
 
@@ skipping 16 matching lines @@
  public:
   virtual bool ShouldOutputCoverageFor(const Library& lib,
                                        const Script& script,
                                        const Class& cls,
                                        const Function& func) const = 0;
   virtual ~CoverageFilter() {}
 };
 
 class CodeCoverage : public AllStatic {
  public:
-  static void Write(Isolate* isolate);
-  static void PrintJSON(Isolate* isolate,
+  static void Write(Thread* thread);
+  static void PrintJSON(Thread* thread,
                         JSONStream* stream,
                         CoverageFilter* filter,
                         bool as_call_sites);
 
  private:
   static void PrintClass(const Library& lib,
                          const Class& cls,
                          const JSONArray& arr,
                          CoverageFilter* filter,
                          bool as_call_sites);
   static void CompileAndAdd(const Function& function,
                             const JSONArray& hits_or_sites,
                             const GrowableArray<intptr_t>& pos_to_line,
                             bool as_call_sites);
 };
 
 }  // namespace dart
 
 #endif  // VM_COVERAGE_H_