Simplified injection process

source/common/background/inject.js

-// This code is executed in the background context
-// source: https://stackoverflow.com/questions/9862182/on-page-load-event-in-chrome-extensions
-//         https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/tabs/executeScript
-
-// Listen for the navigation event
-chrome.webNavigation.onCompleted.addListener (function(details) {
-	// Execute the context script in its own context with "clean DOM"
-	chrome.tabs.executeScript(details.tabId, {
-		file: "/content_scripts/inject.js"
-	});
-});
\ No newline at end of file

source/common/manifest.json

@@ -11,9 +11,7 @@
 	},
 	"permissions": [
 		"storage",
-		"cookies",
-		"tabs",
-		"webNavigation"
+		"cookies"
 	],
 	"optional_permissions": [
 		"webRequest",
@@ -30,12 +28,14 @@
 			],
 		"persistent": true
 	},
-   "content_scripts": [ {
-   "matches":["http://*/", "https://*/"],
-      "all_frames": true,
-      "js": [ "content_scripts/inject.js" ],
-      "run_at": "document_start"
-   } ],
+	"content_scripts": [
+		{
+			"matches":["http://*/", "https://*/"],
+			"all_frames": true,
+			"js": [ "content_scripts/inject.js" ],
+			"run_at": "document_start"
+		}
+	],
 	"web_accessible_resources": [
 		"web_accessible_resources/*"
 	]

source/common/web_accessible_resources/inject.js

 // This code is executed in the context of the window
 
-var veryConvolutedInjection = 4;
+var injectionSuccessful = true;
 
-console.log("Injection completed, try logging the variable veryConvolutedInjection");
\ No newline at end of file
+console.log("Injection completed, try logging the variable injectionSuccessful");
\ No newline at end of file