Chrome – change page navigation keys in pdf viewer

Google Chrome have integrated pdf viewer, the pdf.dll (PPAPI plugin; https://support.google.com/chrome/answer/1060734?hl=en; this software is not open-source but proprietary: https://code.google.com/p/chromium/issues/detail?id=50852#c16). After updating Chrome to 41.0 (pdf.dll version 41, filesize 9279304, md5 ad35b56874ae2f4d3350523c4a1fede5), this plugin changed settings for the keyboard keys like arrows (left, right).

There are PgUp and PgDown keys, which scrolls viewed pdf by one screen up or down. In previous versions (even in pdf.dll version 40, filesize 9171272 bytes, md5 8b56fcfcb0f84733070d97d39fbcd2f6) arrow keys (left and right) allowed to scroll exactly one page (previous page / next page). It was useful for viewing presentations – with any zoom level you can use Right arrow key to go to the next slide, and it will begin at top of screen. When you use Page Down key, the top of page (slide) is not synchronized with top of screen, if the page was not zoomed to have height of some unknown part of the screen (it is impossible to zoom it to have pgdown work as Right arrow key).

Is there any way to restore functionality of left/right arrows of integrated pdf viewer in Chrome, without switching to other binary pdf viewers??
Or is there any other way how can I navigate between pages with every page starting at top of the screen?

Can I migrate from proprietary binary pdf viewer plugin to some open-source pdf viewer, for example to pdf.js (how to integrate pdf.js with Chorme on Windows?)

PS: It is possible to copy older pdf.dll to the application directory of the newer Chrome as temporary solution…