make abp-128.png icon non web accessible

This Review is related to current ticket:
https://issues.adblockplus.org/ticket/172

Chrome works differently under Ubuntu and Chrome.
While I'm getting current error for the icons not listed in web_accessible
resources under Ubuntu:
"Denying load of
chrome-extension://ojacpngaaogckgldgfpfjjpeaegdbgcb/icons/abp-128.png. Resources
must be listed in the web_accessible_resources manifest key in order to be
loaded by pages outside the extension."

But under windows no error message and looks no need to list in web_accessible
resources.
I'll investigate that strange behavior more, maybe it's related to desktop
notifications itself under ubuntu and windows. 

Anyway in Chrome official documentation is written that Resources inside of packages
using manifest_version 2 or above are blocked by default if not whitelisted
through web_accessible param in manifest.json:
https://developer.chrome.com/extensions/manifest/web_accessible_resources#availability


Also not sure if I need to generate data: URL in buildtool(python), or we can
stick to generate it in extension.

[Wladimir Palant, 2014-03-28 14:18:29]

LGTM with the nit addressed. Too bad that we have to use canvas-based hacks for
this rather than simply loading the image via XMLHttpRequest and running btoa()
on it - we would need to load binary data however which means that btoa() isn't
easily applicable.

http://codereview.adblockplus.org/5677191404716032/diff/5629499534213120/back...
File background.js (right):

http://codereview.adblockplus.org/5677191404716032/diff/5629499534213120/back...
background.js:356: var canvas = document.createElement("CANVAS"),
Nit: document.createElement("canvas") please (lowercase tag names are compatible
to both HTML and XHTML).

[saroyanm, 2014-03-28 15:16:02]

On 2014/03/28 14:18:29, Wladimir Palant wrote:
> LGTM with the nit addressed. Too bad that we have to use canvas-based hacks
for
> this rather than simply loading the image via XMLHttpRequest and running
btoa()
> on it - we would need to load binary data however which means that btoa()
isn't
> easily applicable.

I've also succeed with testing with the solution in link below for chrome:
http://stackoverflow.com/questions/8022425/getting-blob-data-from-xhr-request

But looks like it can not work in safari. 
Thanks Wladimir.

http://codereview.adblockplus.org/5677191404716032/diff/5629499534213120/back...
File background.js (right):

http://codereview.adblockplus.org/5677191404716032/diff/5629499534213120/back...
background.js:356: var canvas = document.createElement("CANVAS"),
On 2014/03/28 14:18:29, Wladimir Palant wrote:
> Nit: document.createElement("canvas") please (lowercase tag names are
compatible
> to both HTML and XHTML).

Done.