Check zero-length icon files during extension validation.

chrome/common/extensions/extension_file_util.h

Index: chrome/common/extensions/extension_file_util.h
diff --git a/chrome/common/extensions/extension_file_util.h b/chrome/common/extensions/extension_file_util.h
index ce963a478d85ce6b27c7e1984e3a318aa6dcdce3..49a13cc3a61c5173f4463dac2f67c196ed95dcd6 100644
--- a/chrome/common/extensions/extension_file_util.h
+++ b/chrome/common/extensions/extension_file_util.h
@@ -62,6 +62,9 @@ scoped_refptr<extensions::Extension> LoadExtension(
 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.