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

ppapi/examples/file_chooser/file_chooser.cc

Index: ppapi/examples/file_chooser/file_chooser.cc
diff --git a/ppapi/examples/file_chooser/file_chooser.cc b/ppapi/examples/file_chooser/file_chooser.cc
index 959e649f16fc2f95347f9bc65d4ff8f416e4d0a3..0e9b16a8764fbe558e82fbb8694d5dcfba176280 100644
--- a/ppapi/examples/file_chooser/file_chooser.cc
+++ b/ppapi/examples/file_chooser/file_chooser.cc
@@ -46,9 +46,9 @@ class MyInstance : public pp::InstancePrivate {
     PP_FileChooserMode_Dev mode =
         (multi_select ? PP_FILECHOOSERMODE_OPENMULTIPLE
                       : PP_FILECHOOSERMODE_OPEN);
-    std::string accept_mime_types = (multi_select ? "" : "plain/text");
+    std::string accept_types = (multi_select ? "" : "plain/text");
 
-    chooser_ = pp::FileChooser_Dev(this, mode, accept_mime_types);
+    chooser_ = pp::FileChooser_Dev(this, mode, accept_types);
     chooser_.Show(callback_factory_.NewCallbackWithOutput(
         &MyInstance::ShowSelectedFileNames));
   }