Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=1170063.
The bug only mentions the <kbd>Meta</kbd> key, but given that a similar situation can occur for <kbd>Ctrl</kbd>, it seemed reasonable to also handle that case in the same patch.
The only possible caveat with the patch is that because of the use of `shadow`, things won't work perfectly if either of the prefs are changed *while* the viewer is active. In this case a reload is required in order for it to work correctly, but given that the issue this patch fixes should be quite rare anyway, that seems OK.
For some reason, https://bugzilla.mozilla.org/show_bug.cgi?id=1167053 changed methods of `NetUtil` yet *again*. This patch thus attempts to handle those changes, while keeping the addon backwards compatible.
I've tested this using all current Firefox versions (Nightly, Aurora/DevEdition, Beta, Release, ESR), and things still appears to work correctly.
This patch removes the only remaining CPOW usage from the code-base, and should thus fix https://bugzilla.mozilla.org/show_bug.cgi?id=1071082.
*Note:* This will not fix the "Open With Different Viewer" button in e10s, since clicking it still fails with `frontWindow is null` in the console, but I do believe that that issue is somewhat orthogonal to the current patch.
This checks for both prefs on the understanding that we need to work on older versions of Firefox. If that isn't the case, the first part of the if isn't necessary. This should only land if bug 639134 is resolved - I'd make the patch part of that bug, but AIUI pdfjs's canonical repo is on github, so...
As of Firefox 35, isContentWindowPrivate should be used for DOM windows instead of isWindowPrivate.
See https://bugzilla.mozilla.org/show_bug.cgi?id=1069059 and
http://hg.mozilla.org/mozilla-central/diff/324798b60ba3/toolkit/modules/PrivateBrowsingUtils.jsm
Without this fix, you will get the following error message when Firefox+PDF.js is started:
>
WARNING: content window passed to PrivateBrowsingUtils.isWindowPrivate. Use isContentWindowPrivate instead (but only for frame scripts).
pbu_isWindowPrivate@resource://gre/modules/PrivateBrowsingUtils.jsm:25:14
ChromeActions.prototype.isInPrivateBrowsing@resource://pdf.js/PdfStreamConverter.jsm:237:12
xhr_onreadystatechange@resource://pdf.js/PdfStreamConverter.jsm:545:30
NetworkManager_requestRange@resource://pdf.js/network.js:95:7
NetworkManager_requestRange@resource://pdf.js/network.js:81:14
RangedChromeActions_requestDataRange@resource://pdf.js/PdfStreamConverter.jsm:596:1
RequestListener.prototype.receive@resource://pdf.js/PdfStreamConverter.jsm:705:5
PdfStreamConverter.prototype.onStartRequest/proxy.onStopRequest/<@resource://pdf.js/PdfStreamConverter.jsm:909:11
FirefoxComClosure/<.request@resource://pdf.js/web/viewer.js:529:14
PdfDataRangeTransport_requestDataRange@resource://pdf.js/web/viewer.js:2977:9
transportDataRange@resource://pdf.js/build/pdf.js:2122:13
messageHandlerComObjOnMessage@resource://pdf.js/build/pdf.js:1219:9