Fix a bunch of spelling mistakes :\

src/api.cc

 // Copyright 2007-2008 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 122 matching lines @@
 
 static inline bool ApiCheck(bool condition,
                             const char* location,
                             const char* message) {
   return condition ? true : Utils::ReportApiFailure(location, message);
 }
 
 
 static bool ReportV8Dead(const char* location) {
   FatalErrorCallback callback = GetFatalErrorHandler();
-  callback(location, "V8 is no longer useable");
+  callback(location, "V8 is no longer usable");
   return true;
 }
 
 
 static bool ReportEmptyHandle(const char* location) {
   FatalErrorCallback callback = GetFatalErrorHandler();
   callback(location, "Reading from empty handle");
   return true;
 }
 
 
 /**
- * IsDeadCheck checks that the vm is useable.  If, for instance, the vm has been
+ * IsDeadCheck checks that the vm is usable.  If, for instance, the vm has been
  * out of memory at some point this check will fail.  It should be called on
  * entry to all methods that touch anything in the heap, except destructors
  * which you sometimes can't avoid calling after the vm has crashed.  Functions
  * that call EnsureInitialized or ON_BAILOUT don't have to also call
  * IsDeadCheck.  ON_BAILOUT has the advantage over EnsureInitialized that you
  * can arrange to return if the VM is dead.  This is needed to ensure that no VM
  * heap allocations are attempted on a dead VM.  EnsureInitialized has the
  * advantage over ON_BAILOUT that it actually initializes the VM if this has not
  * yet been done.
  */
@@ skipping 2844 matching lines @@
       reinterpret_cast<HandleScopeImplementer*>(storage);
   List<void**>* blocks_of_archived_thread = thread_local->Blocks();
   ImplementationUtilities::HandleScopeData* handle_data_of_archived_thread =
       &thread_local->handle_scope_data_;
   Iterate(v, blocks_of_archived_thread, handle_data_of_archived_thread);
 
   return storage + ArchiveSpacePerThread();
 }
 
 } }  // namespace v8::internal