Pepper: Simplify manifest download logic.

components/nacl/renderer/manifest_downloader.h

 // Copyright 2014 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.
 
 #include <string>
 
 #include "base/callback.h"
 #include "ppapi/c/private/ppb_nacl_private.h"
 #include "third_party/WebKit/public/platform/WebURLLoaderClient.h"
 
 namespace blink {
 struct WebURLError;
 class WebURLLoader;
 class WebURLResponse;
 }
 
 namespace nacl {
 
 // Downloads a NaCl manifest (.nmf) and returns the contents of the file to
 // caller through a callback.
 class ManifestDownloader : public blink::WebURLLoaderClient {
  public:
   typedef base::Callback<void(PP_NaClError, const std::string&)>
       ManifestDownloaderCallback;
 
   ManifestDownloader(bool is_installed, ManifestDownloaderCallback cb);
   virtual ~ManifestDownloader();
 
+  // This is a pretty arbitrary limit on the byte size of the NaCl manifest
+  // file.
+  // Note that the resulting string object has to have at least one byte extra
+  // for the null termination character.
+  static const size_t kNaClManifestMaxFileBytes = 1024 * 1024;
+
  private:
   // WebURLLoaderClient implementation.
   virtual void didReceiveResponse(blink::WebURLLoader* loader,
                                   const blink::WebURLResponse& response);
   virtual void didReceiveData(blink::WebURLLoader* loader,
                               const char* data,
                               int data_length,
                               int encoded_data_length);
   virtual void didFinishLoading(blink::WebURLLoader* loader,
                                 double finish_time,
                                 int64_t total_encoded_data_length);
   virtual void didFail(blink::WebURLLoader* loader,
                        const blink::WebURLError& error);
 
   bool is_installed_;
   ManifestDownloaderCallback cb_;
   std::string buffer_;
   int status_code_;
   PP_NaClError pp_nacl_error_;
 };
 
 }  // namespace nacl