[api] Templatize do_callback parameter in CallDepthScope

src/isolate.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_ISOLATE_H_
 #define V8_ISOLATE_H_
 
 #include <memory>
 #include <queue>
 #include <set>
@@ skipping 1479 matching lines @@
   SaveContext* prev() { return prev_; }
 
   // Returns true if this save context is below a given JavaScript frame.
   bool IsBelowFrame(StandardFrame* frame) {
     return (c_entry_fp_ == 0) || (c_entry_fp_ > frame->sp());
   }
 
   Isolate* isolate() { return isolate_; }
 
  private:
-  Isolate* isolate_;
+  Isolate* const isolate_;
   Handle<Context> context_;
-  SaveContext* prev_;
+  SaveContext* const prev_;
   Address c_entry_fp_;
 };
 
 
 class AssertNoContextChange BASE_EMBEDDED {
 #ifdef DEBUG
  public:
   explicit AssertNoContextChange(Isolate* isolate);
   ~AssertNoContextChange() {
     DCHECK(isolate_->context() == *context_);
@@ skipping 159 matching lines @@
 
   EmbeddedVector<char, 128> filename_;
   FILE* file_;
   int scope_depth_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ISOLATE_H_