Modified the pepper file chooser API to support filtering files by extensions.

content/public/common/file_chooser_params.h

Index: content/public/common/file_chooser_params.h
diff --git a/content/public/common/file_chooser_params.h b/content/public/common/file_chooser_params.h
index 7807cbd2334f8be67607c3f15e70fd31b8cc9bed..ef64a95e5c5cbd343b796c2b7acadefcc32a6023 100644
--- a/content/public/common/file_chooser_params.h
+++ b/content/public/common/file_chooser_params.h
@@ -43,8 +43,8 @@ struct CONTENT_EXPORT FileChooserParams {
   // Default file name to select in the dialog.
   FilePath default_file_name;
 
-  // A list of valid lower-cased MIME types specified in an input element. It is
-  // used to restrict selectable files to such types.
+  // A list of valid lower-cased MIME types or file extensions specified in an
+  // input element. It is used to restrict selectable files to such types.
   std::vector<string16> accept_types;
 };