move downloads permission to optionals. Fixes #139

src/manifest.json

@@ -4,12 +4,8 @@
 	"manifest_version": 2,
 	"description": "Blazing fast & offline playground for your web experiments",
 	"homepage_url": "https://webmakerapp.com",
-	"permissions": [
+	"permissions": ["storage", "tabs", "<all_urls>"],
-		"storage",
+	"optional_permissions": ["downloads"],
-		"tabs",
-		"<all_urls>",
-		"downloads"
-	],
 	"content_security_policy": "script-src 'self' filesystem: http://localhost:* https://localhost:* https://ajax.googleapis.com https://code.jquery.com https://cdnjs.cloudflare.com https://unpkg.com https://maxcdn.com https://cdn77.com https://maxcdn.bootstrapcdn.com https://cdn.jsdelivr.net/ https://*.stripe.com/ https://builds.framerjs.com/ https://rawgit.com https://wzrd.in https://www.google-analytics.com 'unsafe-eval'; object-src 'self'",
 	"options_ui": {
 		"page": "options.html",

src/script.js

@@ -1451,7 +1451,37 @@ runBtn, searchInput, consoleEl, consoleLogEl, logCountEl, fontStyleTag, fontStyl
 		);
 	}
 
+	function handleDownloadsPermission() {
+		var d = deferred();
+		chrome.permissions.contains(
+			{
+				permissions: ['downloads']
+			},
+			function(result) {
+				if (result) {
+					d.resolve();
+				} else {
+					chrome.permissions.request(
+						{
+							permissions: ['downloads']
+						},
+						function(granted) {
+							if (granted) {
+								trackEvent('fn', 'downloadsPermGiven');
+								d.resolve();
+							} else {
+								d.reject();
+							}
+						}
+					);
+				}
+			}
+		);
+		return d.promise;
+	}
+
 	scope.takeScreenshot = function(e) {
+		handleDownloadsPermission().then(() => {
 			// Hide tooltips so that they don't show in the screenshot
 			var s = document.createElement('style');
 			s.textContent =
@@ -1495,6 +1525,8 @@ runBtn, searchInput, consoleEl, consoleLogEl, logCountEl, fontStyleTag, fontStyl
 			}, 50);
 
 			trackEvent('ui', 'takeScreenshotBtnClick');
+		});
+
 		e.preventDefault();
 	};