Check zero-length icon files during extension validation.

chrome/common/extensions/extension_file_util.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_COMMON_EXTENSIONS_EXTENSION_FILE_UTIL_H_
 #define CHROME_COMMON_EXTENSIONS_EXTENSION_FILE_UTIL_H_
 
 #include <string>
 #include <map>
 
@@ skipping 44 matching lines @@
     const std::string& extension_id,
     extensions::Extension::Location location,
     int flags,
     std::string* error);
 
 // Loads an extension manifest from the specified directory. Returns NULL
 // on failure, with a description of the error in |error|.
 base::DictionaryValue* LoadManifest(const FilePath& extension_root,
                                     std::string* error);
 
+// Returns true if the given file path exists and is not zero-length.
+bool ValidateFilePath(const FilePath& path);
+
 // Returns true if the given extension object is valid and consistent.
 // May also append a series of warning messages to |warnings|, but they
 // should not prevent the extension from running.
 //
 // Otherwise, returns false, and a description of the error is
 // returned in |error|.
 bool ValidateExtension(const extensions::Extension* extension,
                        std::string* error,
                        extensions::Extension::InstallWarningVector* warnings);
 
@@ skipping 48 matching lines @@
 FilePath GetUserDataTempDir();
 
 // Helper function to delete files. This is used to avoid ugly casts which
 // would be necessary with PostMessage since file_util::Delete is overloaded.
 // TODO(skerner): Make a version of Delete that is not overloaded in file_util.
 void DeleteFile(const FilePath& path, bool recursive);
 
 }  // namespace extension_file_util
 
 #endif  // CHROME_COMMON_EXTENSIONS_EXTENSION_FILE_UTIL_H_