Fix a bunch of spelling mistakes :\

src/top.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 20 matching lines @@
 #include "frames-inl.h"
 
 namespace v8 { namespace internal {
 
 
 #define RETURN_IF_SCHEDULED_EXCEPTION() \
   if (Top::has_scheduled_exception()) return Top::PromoteScheduledException()
 
 // Top has static variables used for JavaScript execution.
 
-class SaveContext;  // Forward decleration.
+class SaveContext;  // Forward declaration.
 
 class ThreadLocalTop BASE_EMBEDDED {
  public:
   // The context where the current execution method is created and for variable
   // lookups.
   Context* context_;
   Object* pending_exception_;
   bool has_pending_message_;
   const char* pending_message_;
   Object* pending_message_obj_;
@@ skipping 259 matching lines @@
 
   friend class SaveContext;
   friend class AssertNoContextChange;
   friend class ExecutionAccess;
 
   static void FillCache();
 };
 
 
 // If the GCC version is 4.1.x or 4.2.x an additional field is added to the
-// class as a workarround for a bug in the generated code found with these
+// class as a work around for a bug in the generated code found with these
 // versions of GCC. See V8 issue 122 for details.
 class SaveContext BASE_EMBEDDED {
  public:
   SaveContext() :
       context_(Top::context()),
 #if __GNUC_VERSION__ >= 40100 && __GNUC_VERSION__ < 40300
       dummy_(Top::context()),
 #endif
       prev_(Top::save_context()) {
     Top::set_save_context(this);
@@ skipping 49 matching lines @@
 
 class ExecutionAccess BASE_EMBEDDED {
  public:
   ExecutionAccess();
   ~ExecutionAccess();
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_TOP_H_