Update V8 to r7427: Initial merge by git

As required by WebKit r82507

Change-Id: I7ae83ef3f689356043b4929255b7c1dd31d8c5df
diff --git a/src/vm-state.h b/src/vm-state.h
index df7fb30..11fc6d6 100644
--- a/src/vm-state.h
+++ b/src/vm-state.h
@@ -28,7 +28,7 @@
 #ifndef V8_VM_STATE_H_
 #define V8_VM_STATE_H_
 
-#include "top.h"
+#include "isolate.h"
 
 namespace v8 {
 namespace internal {
@@ -36,15 +36,16 @@
 class VMState BASE_EMBEDDED {
 #ifdef ENABLE_VMSTATE_TRACKING
  public:
-  inline explicit VMState(StateTag tag);
+  inline VMState(Isolate* isolate, StateTag tag);
   inline ~VMState();
 
  private:
+  Isolate* isolate_;
   StateTag previous_tag_;
 
 #else
  public:
-  explicit VMState(StateTag state) {}
+  VMState(Isolate* isolate, StateTag state) {}
 #endif
 };
 
@@ -52,13 +53,14 @@
 class ExternalCallbackScope BASE_EMBEDDED {
 #ifdef ENABLE_LOGGING_AND_PROFILING
  public:
-  inline explicit ExternalCallbackScope(Address callback);
+  inline ExternalCallbackScope(Isolate* isolate, Address callback);
   inline ~ExternalCallbackScope();
  private:
+  Isolate* isolate_;
   Address previous_callback_;
 #else
  public:
-  explicit ExternalCallbackScope(Address callback) {}
+  ExternalCallbackScope(Isolate* isolate, Address callback) {}
 #endif
 };