NaCl SDK: Remove some unused variables in url_loader.cc example

native_client_sdk/src/examples/api/url_loader/url_loader.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This example demonstrates how to load content of the page into NaCl module.
 
 #include <cstdio>
 #include <string>
 #include "ppapi/cpp/instance.h"
 #include "ppapi/cpp/module.h"
 #include "ppapi/cpp/url_loader.h"
 #include "ppapi/cpp/var.h"
 
 #include "url_loader_handler.h"
 
 // These are the method names as JavaScript sees them.
 namespace {
 const char* const kLoadUrlMethodId = "getUrl";
 static const char kMessageArgumentSeparator = ':';
-
-// Exception strings.  These are passed back to the browser when errors
-// happen during property accesses or method calls.
-const char* const kExceptionStartFailed = "URLLoaderHandler::Start() failed";
-const char* const kExceptionURLNotAString = "URL is not a string";
 }  // namespace
 
 class URLLoaderInstance : public pp::Instance {
  public:
   explicit URLLoaderInstance(PP_Instance instance) : pp::Instance(instance) {}
   virtual ~URLLoaderInstance() {}
 
   // Called by the browser to handle the postMessage() call in Javascript.
   // The message in this case is expected to contain the string 'getUrl'
   // followed by a ':' separator, then the URL to fetch.  If a valid message
@@ skipping 35 matching lines @@
 
   // Create and return a URLLoaderInstance object.
   virtual pp::Instance* CreateInstance(PP_Instance instance) {
     return new URLLoaderInstance(instance);
   }
 };
 
 namespace pp {
 Module* CreateModule() { return new URLLoaderModule(); }
 }  // namespace pp