It is well known that Google can load PDF files properly, via PDF Viewer extensions.
My aim is to open a PDF file, and use the extensions like Google Dictionary, dict.cc, Google Translator on this file. These extensions work like this: You select a word by double clicking (just selection is enough) and its description pops out immediately.
No matter which extension I use, this function seems to work on only web pages, and not on PDF files, even though they both contain selectable text.
Is there any way to get these extensions to cooperate properly?