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

runtime/vm/os_android.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"
 #if defined(TARGET_OS_ANDROID)
 
 #include "vm/os.h"
 
 #include <android/log.h>  // NOLINT
@@ skipping 58 matching lines @@
                       uword prologue_offset,
                       uword size,
                       bool optimized) {
     Dart_FileWriteCallback file_write = Isolate::file_write_callback();
     if ((file_write == NULL) || (out_file_ == NULL)) {
       return;
     }
     const char* format = "%" Px " %" Px " %s%s\n";
     const char* marker = optimized ? "*" : "";
     intptr_t len = OS::SNPrint(NULL, 0, format, base, size, marker, name);
-    char* buffer = Isolate::Current()->current_zone()->Alloc<char>(len + 1);
+    char* buffer = Thread::Current()->zone()->Alloc<char>(len + 1);
     OS::SNPrint(buffer, len + 1, format, base, size, marker, name);
     (*file_write)(buffer, len, out_file_);
   }
 
  private:
   void* out_file_;
 
   DISALLOW_COPY_AND_ASSIGN(PerfCodeObserver);
 };
 
@@ skipping 12 matching lines @@
                       uword size,
                       bool optimized) {
     if (prologue_offset > 0) {
       // In order to ensure that gdb sees the first instruction of a function
       // as the prologue sequence we register two symbols for the cases when
       // the prologue sequence is not the first instruction:
       // <name>_entry is used for code preceding the prologue sequence.
       // <name> for rest of the code (first instruction is prologue sequence).
       const char* kFormat = "%s_%s";
       intptr_t len = OS::SNPrint(NULL, 0, kFormat, name, "entry");
-      char* pname = Isolate::Current()->current_zone()->Alloc<char>(len + 1);
+      char* pname = Thread::Current()->zone()->Alloc<char>(len + 1);
       OS::SNPrint(pname, (len + 1), kFormat, name, "entry");
       DebugInfo::RegisterSection(pname, base, size);
       DebugInfo::RegisterSection(name,
                                  (base + prologue_offset),
                                  (size - prologue_offset));
     } else {
       DebugInfo::RegisterSection(name, base, size);
     }
   }
 
@@ skipping 292 matching lines @@
 }
 
 
 void OS::Exit(int code) {
   exit(code);
 }
 
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_ANDROID)