Migrate most uses of Isolate::current_zone to Thread::zone.

runtime/vm/debugger.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/debugger.h"
 
 #include "include/dart_api.h"
 
 #include "vm/code_generator.h"
 #include "vm/code_patcher.h"
@@ skipping 386 matching lines @@
   const String& func_name = String::Handle(func.name());
   Class& func_class = Class::Handle(func.Owner());
   String& class_name = String::Handle(func_class.Name());
 
   const char* kFormat = "%s%s%s";
   intptr_t len = OS::SNPrint(NULL, 0, kFormat,
       func_class.IsTopLevel() ? "" : class_name.ToCString(),
       func_class.IsTopLevel() ? "" : ".",
       func_name.ToCString());
   len++;  // String terminator.
-  char* chars = Isolate::Current()->current_zone()->Alloc<char>(len);
+  char* chars = Thread::Current()->zone()->Alloc<char>(len);
   OS::SNPrint(chars, len, kFormat,
               func_class.IsTopLevel() ? "" : class_name.ToCString(),
               func_class.IsTopLevel() ? "" : ".",
               func_name.ToCString());
   return chars;
 }
 
 
 // Returns true if function contains the token position in the given script.
 static bool FunctionContains(const Function& func,
@@ skipping 595 matching lines @@
   }
   UNREACHABLE();
   return Object::null();
 }
 
 
 const char* ActivationFrame::ToCString() {
   const String& url = String::Handle(SourceUrl());
   intptr_t line = LineNumber();
   const char* func_name = Debugger::QualifiedFunctionName(function());
-  return Isolate::Current()->current_zone()->
+  return Thread::Current()->zone()->
       PrintToString("[ Frame pc(0x%" Px ") fp(0x%" Px ") sp(0x%" Px ")\n"
                     "\tfunction = %s\n"
                     "\turl = %s\n"
                     "\tline = %" Pd "\n"
                     "\tcontext = %s\n"
                     "\tcontext level = %" Pd " ]\n",
                     pc(), fp(), sp(),
                     func_name,
                     url.ToCString(),
                     line,
@@ skipping 1957 matching lines @@
 }
 
 
 void Debugger::RegisterCodeBreakpoint(CodeBreakpoint* bpt) {
   ASSERT(bpt->next() == NULL);
   bpt->set_next(code_breakpoints_);
   code_breakpoints_ = bpt;
 }
 
 }  // namespace dart