AlwaysKillSticky/background.js

/*	Enables the page action (i.e., the browser toolbar icon).
	*/
chrome.runtime.onInstalled.addListener(() => {
	chrome.declarativeContent.onPageChanged.removeRules(undefined, () => {
		chrome.declarativeContent.onPageChanged.addRules([{
			conditions: [ new chrome.declarativeContent.PageStateMatcher({
				pageUrl: { },
			})
			], actions: [ new chrome.declarativeContent.ShowPageAction() ]
		}]);
	});
});

/*	Toggle the toolbar icon based on whether stickies are, or are not, set to
	be killed on the current tab.

	This listener receives a message from the content script (contentScript.js);
	the content script actually determines what the settings for the current
	tab are.
	*/
chrome.runtime.onMessage.addListener((request, sender, sendResponse) => {
	let icons = request.killingStickies ? {
			"16":	"images/ASK_on_16.png",
			"32":	"images/ASK_on_32.png",
			"48":	"images/ASK_on_48.png",
			"128":	"images/ASK_on_128.png"
	} : {
			"16":	"images/ASK_off_16.png",
			"32":	"images/ASK_off_32.png",
			"48":	"images/ASK_off_48.png",
			"128":	"images/ASK_off_128.png"
	};
	chrome.pageAction.setIcon({
		path: icons,
		tabId: sender.tab.id
	});
});