Make snapshot.h usable without objects-inl.h header.

src/snapshot/snapshot.h

Index: src/snapshot/snapshot.h
diff --git a/src/snapshot/snapshot.h b/src/snapshot/snapshot.h
index dabc694d50a7c01ecc13774f2b9a32c7751f5260..1379644fd85861e01ca12cd357799ec3675b8751 100644
--- a/src/snapshot/snapshot.h
+++ b/src/snapshot/snapshot.h
@@ -5,7 +5,6 @@
 #ifndef V8_SNAPSHOT_SNAPSHOT_H_
 #define V8_SNAPSHOT_SNAPSHOT_H_
 
-#include "src/isolate.h"
 #include "src/snapshot/serialize.h"
 
 namespace v8 {
@@ -41,11 +40,7 @@ class Snapshot : public AllStatic {
       Isolate* isolate, Handle<JSGlobalProxy> global_proxy,
       Handle<FixedArray>* outdated_contexts_out);
 
-  static bool HaveASnapshotToStartFrom(Isolate* isolate) {
-    // Do not use snapshots if the isolate is used to create snapshots.
-    return isolate->snapshot_blob() != NULL &&
-           isolate->snapshot_blob()->data != NULL;
-  }
+  static bool HaveASnapshotToStartFrom(Isolate* isolate);
 
   static bool EmbedsScript(Isolate* isolate);