I know this may be a long shot, but I'm building a fork of Android Chromium and trying to find a way to support viewing PDF files from external sites in-browser, without downloading the file.
It's a strict business rule that the PDFs cannot be stored on the device.
I've noticed that mobile Safari on iOS devices does something similar to this and shows the PDF in-browser.
I have found this post which is helpful, but does not necessarily help me with the fact that I do not control what the external site hosting the PDF does.
Any help would be greatly appreciated.