Page action icon now updated immediately on state toggle; some refactoring

background.js

 	};
 	chrome.pageAction.setIcon({
 		path: icons,
-		tabId: sender.tab.id
+		tabId: request.tabID || sender.tab.id
 	});
 });

contentScript.js

 	return shouldKillSticky;
 }
 
-/*	This function sends a message to the background script (background.js), 
-	which then updates the page action icon (i.e., the browser toolbar icon)
-	to reflect whether killing stickies is enabled on the current page.
-	*/
-function updateIcon(shouldKillSticky) {
-	chrome.runtime.sendMessage({ "killingStickies" : shouldKillSticky });
-}
-
 /******************/
 /* INITIALIZATION */
 /******************/

functions.js

 /* HELPERS */
 /***********/
 
+/*	This function sends a message to the background script (background.js), 
+	which then updates the page action icon (i.e., the browser toolbar icon)
+	to reflect whether killing stickies is enabled on the current page.
+	*/
+function updateIcon(shouldKillSticky, tabID) {
+	chrome.runtime.sendMessage({ "killingStickies" : shouldKillSticky, "tabID": tabID });
+}
+
 /*	This is the code that actually does the sticky killing! It simply selects
 	all elements whose 'position' CSS property has a computed value of either
 	'sticky' or 'fixed', and removes those elements.

popup.js

 	// Retrieve saved settings.
 	chrome.tabs.query({currentWindow: true, active: true}, (tabs) => {
 		AKS.activeTabLocation = tabs[0].url;
+		AKS.activeTabID = tabs[0].id;
 		chrome.storage.sync.get([ "matchingPatterns", "exclusionPatterns", "mode" ], (result) => {
 			updateState(result);
 			updateUIState();
 
 	// Listener for main button.
 	document.querySelector("button.main-button").addActivateEvent((event) => {
+		/*	This doesn’t actually kill the stickies yet; that’s below, in the 
+			callback to storage.sync.set. */
 		toggleState();
 
+		// Prepare the changes for saving.
 		var changes = {
 			"exclusionPatterns": AKS.exclusionPatterns.join("\n"),
 			"mode": AKS.mode
 		};
 		if (AKS.mode == "blacklist")
 			changes.matchingPatterns = AKS.matchingPatterns.join("\n");
+
+		// Save the changes.
 		chrome.storage.sync.set(changes, () => {
+			// Update the UI, once changes are saved.
 			updateUIState();
 			let reloadButton = document.querySelector("button.reload-button");
+
+			/*	If need be, actually kill stickies on the current page. 
+				Otherwise, show the reload button. */
+			let shouldKillSticky = AKS.pageMatched && !AKS.pageExcluded;
 			if (AKS.pageMatched && !AKS.pageExcluded) {
 				chrome.tabs.executeScript(null, { code: 'killSticky()' });
 				reloadButton.classList.toggle("active", false);
 			} else {
 				reloadButton.classList.toggle("active", true);
 			}
+
+			// Update the page action (toolbar) icon.
+			updateIcon(shouldKillSticky, AKS.activeTabID);
 		});
 	});