Move GetRootListIndex into Heap.

src/heap/heap.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_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 
 #include "src/allocation.h"
@@ skipping 1148 matching lines @@
     kStringTableRootIndex,
 
 #define ROOT_INDEX_DECLARATION(type, name, camel_name) k##camel_name##RootIndex,
     SMI_ROOT_LIST(ROOT_INDEX_DECLARATION)
 #undef ROOT_INDEX_DECLARATION
     kRootListLength,
     kStrongRootListLength = kStringTableRootIndex,
     kSmiRootsStart = kStringTableRootIndex + 1
   };
 
+  // Get the root list index for {object} if such a root list index exists.
+  bool GetRootListIndex(Handle<HeapObject> object,
+                        Heap::RootListIndex* index_return);
+
   Object* root(RootListIndex index) { return roots_[index]; }
 
   STATIC_ASSERT(kUndefinedValueRootIndex ==
                 Internals::kUndefinedValueRootIndex);
   STATIC_ASSERT(kNullValueRootIndex == Internals::kNullValueRootIndex);
   STATIC_ASSERT(kTrueValueRootIndex == Internals::kTrueValueRootIndex);
   STATIC_ASSERT(kFalseValueRootIndex == Internals::kFalseValueRootIndex);
   STATIC_ASSERT(kempty_stringRootIndex == Internals::kEmptyStringRootIndex);
 
   // Generated code can embed direct references to non-writable roots if
@@ skipping 1429 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_HEAP_H_