Rollback of r12868, r12849 on bleeding_edge.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index dfe95f5287a1289e88f7233cad205ceef38be4d5..ae14302306ed06ca9a205af214f8f621ca36e7c8 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -155,7 +155,6 @@ namespace internal {
   V(Smi, construct_stub_deopt_pc_offset, ConstructStubDeoptPCOffset)           \
   V(Smi, getter_stub_deopt_pc_offset, GetterStubDeoptPCOffset)                 \
   V(Smi, setter_stub_deopt_pc_offset, SetterStubDeoptPCOffset)                 \
-  V(Map, external_map, ExternalMap)                                            \
   V(JSObject, observation_state, ObservationState)
 
 #define ROOT_LIST(V)                                  \
@@ -666,9 +665,6 @@ class Heap {
   // Allocates a serialized scope info.
   MUST_USE_RESULT MaybeObject* AllocateScopeInfo(int length);
 
-  // Allocates an External object for v8's external API.
-  MUST_USE_RESULT MaybeObject* AllocateExternal(void* value);
-
   // Allocates an empty PolymorphicCodeCache.
   MUST_USE_RESULT MaybeObject* AllocatePolymorphicCodeCache();