Throw a more descriptive exception when blocking 'eval' via CSP.

include/v8.h

 // Copyright 2012 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 3710 matching lines @@
    */
   void AllowCodeGenerationFromStrings(bool allow);
 
   /**
    * Returns true if code generation from strings is allowed for the context.
    * For more details see AllowCodeGenerationFromStrings(bool) documentation.
    */
   bool IsCodeGenerationFromStringsAllowed();
 
   /**
+   * Sets the error description for the exception that is thrown when
+   * code generation from strings is not allowed and 'eval' or the 'Function'
+   * constructor are called.
+   */
+  void SetErrorMessageForCodeGenerationFromStrings(Handle<String> message);
+
+  /**
    * Stack-allocated class which sets the execution context for all
    * operations executed within a local scope.
    */
   class Scope {
    public:
     explicit inline Scope(Handle<Context> context) : context_(context) {
       context_->Enter();
     }
     inline ~Scope() { context_->Exit(); }
    private:
@@ skipping 869 matching lines @@
 
 
 }  // namespace v8
 
 
 #undef V8EXPORT
 #undef TYPE_CHECK
 
 
 #endif  // V8_H_