- Ensure that BaseIsolate is only used to break the header include cycles.

runtime/vm/handles.h

Index: runtime/vm/handles.h
===================================================================
--- runtime/vm/handles.h	(revision 35767)
+++ runtime/vm/handles.h	(working copy)
@@ -297,7 +297,7 @@
 // }
 class HandleScope : public StackResource {
  public:
-  explicit HandleScope(BaseIsolate* isolate);
+  explicit HandleScope(Isolate* isolate);
   ~HandleScope();
 
  private:
@@ -329,7 +329,7 @@
 #if defined(DEBUG)
 class NoHandleScope : public StackResource {
  public:
-  explicit NoHandleScope(BaseIsolate* isolate);
+  explicit NoHandleScope(Isolate* isolate);
   NoHandleScope();
   ~NoHandleScope();
 
@@ -339,7 +339,7 @@
 #else  // defined(DEBUG)
 class NoHandleScope : public ValueObject {
  public:
-  explicit NoHandleScope(BaseIsolate* isolate) { }
+  explicit NoHandleScope(Isolate* isolate) { }
   NoHandleScope() { }
   ~NoHandleScope() { }