[Chrome extension] Added JSDocs to pdfHandler.js

And a small refactor to reduce the LOC in the onHeadersReceived
callback, to improve the readability of the code.
[CRX] Don't intercept download of PDF attachment

Fixes #3426
Syncing order of JS files in viewer.html and make.js. See #3414
[Browsing history] Remove 'beforeunload' to enable caching and prevent duplicate entries
Removes foreign for Firefox CSS prefixes
Fixes ASCIIHex decoding
Fix printing behaviour in Chrome

Two major issues:
1. Border/shadow around every page. Removed by adding "border:none".
2. Added "overflow:visible" (overrides "overflow:auto") in #viewContainer.
   This solves two problems:
   - It prevents scrollbars from appearing.
   - Every "page" is automatically resized to fit on a printed page,
     just like the Firefox.
To see what's wrong, here's a picture of how PDF.js rendered the pdf in
 Chrome (using "Print to PDF" feature of Chrome):
 https://robwu.nl/pdfjs/pdfjs-print-with-chromium-28.pdf

Successfully tested with Chrome 28 and Firefox 22.

Solves #3445
Disable Google Translate on viewer in Chrome.

test/pdfs/yo01.pdf triggered "This page is in Japanese. Would you like
to translate it?" info bar in Chrome.
Use dummy font for testing when pdf fonts are loaded.
Bug 881152 - hdpi/xhdpi resolution assets and layout for PDF Viewer app
 1. Add 1.5x assets
 2. specify the background size of page number section
Merge pull request #3464 from yurydelendik/bug889327

Fixes ASCIIHex decoding
Merge pull request #3457 from yurydelendik/remove-prefixes

Removes foreign for Firefox CSS prefixes
Merge pull request #3440 from peerlibrary/syncing-order

Syncing order of JS files in viewer.html and make.js. See #3414
Merge pull request #3430 from Rob--W/crx-download-pdf

Chrome extension: Do not intercept PDF downloads if it's target is a frame
[CRX] Improved navigation detection.

A user reported that the PDF Viewer is not rendered on Dropbox,
(Chrome on Mac OS X). This is apparently caused by the fact that the
PDF file is loaded in an iframe in such a way that the tabs.onUpdated
event is not triggered.

This patch switches to the webNavigation event API, which improves the
reliability of the navigation detection.

Unfortunately Opera 15 does not support the webNavigation API, so the
old (tabs.onUpdated) method is used (feature-detection is used, so
whenever Opera decides to implement this API, it will profit from it).
Add atob polyfill. Remove uneeded data uri polyfill.
Merge pull request #3479 from RudyLu/mutlires_1.5

Bug 881152 - hdpi/xhdpi resolution assets and layout for PDF Viewer app
Merge pull request #3473 from Rob--W/chrome-printing

Fix printing behaviour in Chrome
[CRX] Delay render of viewer if needed...

Sometimes, the viewer did not render for PDF files in an iframe,
because document.readyState not reaching "complete".

Deferring window.stop() until the root element is placed in the
document fixes the problem (typically a few ten milliseconds).
Merge pull request #3449 from Snuffleupagus/history-remove-beforeunload

[Browsing history] Remove 'beforeunload' to enable caching and prevent duplicate entries