I got it. Format between config file of CKEditor and option of CKEditor4 is different a little. Try to change your "Other configuration" (From " = " to ":").
toolbarCanCollapse:false,
removePlugins:'elementspath',
removeButtons:'Subscript,Superscript',
resize_enabled:false,
autogrow:false,
entities:false,
extraPlugins:'smiley,font,oembed,widget',
oembed_maxWidth:'560',
oembed_maxHeight:'315',
oembed_WrapperClass:'embededContent'
Reference about oembed plugin:
http://www.question2answer.org/qa/38975/tips-media-oembed-plugin-with-ckeditor4-plugin
Note: oembed plugin depends on some other plugins (widget, dialog, lineutils,clipboard). You can confirm dependencies with each plugin download dialog. Especially, in new CKEditor, this dependencies seems to be changed. Please be careful.