Make sure that HttpRequestHeaders contains valid key-value pairs.

chrome/browser/extensions/api/downloads/downloads_api.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_DOWNLOADS_DOWNLOADS_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_DOWNLOADS_DOWNLOADS_API_H_
 
 #include <set>
 #include <string>
 
@@ skipping 28 matching lines @@
 namespace download_extension_errors {
 
 // Errors that can be returned through chrome.runtime.lastError.message.
 extern const char kEmptyFile[];
 extern const char kFileAlreadyDeleted[];
 extern const char kFileNotRemoved[];
 extern const char kIconNotFound[];
 extern const char kInvalidDangerType[];
 extern const char kInvalidFilename[];
 extern const char kInvalidFilter[];
-extern const char kInvalidHeader[];
+extern const char kInvalidHeaderName[];
+extern const char kInvalidHeaderValue[];
+extern const char kInvalidHeaderUnsafe[];
 extern const char kInvalidId[];
 extern const char kInvalidOrderBy[];
 extern const char kInvalidQueryLimit[];
 extern const char kInvalidState[];
 extern const char kInvalidURL[];
 extern const char kInvisibleContext[];
 extern const char kNotComplete[];
 extern const char kNotDangerous[];
 extern const char kNotInProgress[];
 extern const char kNotResumable[];
@@ skipping 341 matching lines @@
   ScopedObserver<extensions::ExtensionRegistry,
                  extensions::ExtensionRegistryObserver>
       extension_registry_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionDownloadsEventRouter);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_DOWNLOADS_DOWNLOADS_API_H_