Revert 22105 "Remove static initializer from isolate"

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index a9fae688fc20d19afde0ce9dde0b4f82f6932636..157839fb6459bdbd121c92c72d7d0d869ac887d6 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -486,6 +486,13 @@ class Isolate {
 
   static void GlobalTearDown();
 
+  static void SetCrashIfDefaultIsolateInitialized();
+  // Ensures that process-wide resources and the default isolate have been
+  // allocated. It is only necessary to call this method in rare cases, for
+  // example if you are using V8 from within the body of a static initializer.
+  // Safe to call multiple times.
+  static void EnsureDefaultIsolate();
+
   // Find the PerThread for this particular (isolate, thread) combination
   // If one does not yet exist, return null.
   PerIsolateThreadData* FindPerThreadDataForThisThread();
@@ -1083,8 +1090,6 @@ class Isolate {
   void CountUsage(v8::Isolate::UseCounterFeature feature);
 
  private:
-  static void EnsureInitialized();
-
   Isolate();
 
   friend struct GlobalState;
@@ -1144,7 +1149,7 @@ class Isolate {
   };
 
   // This mutex protects highest_thread_id_ and thread_data_table_.
-  static base::LazyMutex process_wide_mutex_;
+  static base::Mutex process_wide_mutex_;
 
   static base::Thread::LocalStorageKey per_isolate_thread_data_key_;
   static base::Thread::LocalStorageKey isolate_key_;