Fix web view sometimes not loading correctly

Fixes #929.

scripts/vscode.patch

@@ -1109,7 +1109,7 @@ index 0d2d53003b..03489411bb 100644
  			group: '5_update',
  			command: {
 diff --git a/src/vs/workbench/contrib/webview/browser/pre/index.html b/src/vs/workbench/contrib/webview/browser/pre/index.html
-index ac53ce590e..69dbbd859c 100644
+index ac53ce590e..5411601483 100644
 --- a/src/vs/workbench/contrib/webview/browser/pre/index.html
 +++ b/src/vs/workbench/contrib/webview/browser/pre/index.html
 @@ -4,7 +4,7 @@
@@ -1117,12 +1117,12 @@ index ac53ce590e..69dbbd859c 100644
  	<meta charset="UTF-8">
  	<meta http-equiv="Content-Security-Policy"
 -		content="default-src 'none'; script-src 'self'; frame-src 'self'; style-src 'unsafe-inline'; worker-src 'self';" />
-+		content="default-src 'none'; script-src 'self' 'unsafe-inline'; frame-src 'self'; style-src 'self' 'unsafe-inline'; worker-src 'self'; img-src https: data:; font-src 'self';" />
++		content="default-src 'none'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; frame-src 'self'; style-src 'self' 'unsafe-inline'; worker-src 'self'; img-src https: data:; font-src 'self';" />
  
  	<meta name="viewport" content="width=device-width, initial-scale=1.0">
  	<meta http-equiv="X-UA-Compatible" content="ie=edge">
 diff --git a/src/vs/workbench/contrib/webview/browser/pre/main.js b/src/vs/workbench/contrib/webview/browser/pre/main.js
-index 63585fc25c..f49b63e024 100644
+index 63585fc25c..16102b89f1 100644
 --- a/src/vs/workbench/contrib/webview/browser/pre/main.js
 +++ b/src/vs/workbench/contrib/webview/browser/pre/main.js
 @@ -256,7 +256,7 @@
@@ -1134,19 +1134,15 @@ index 63585fc25c..f49b63e024 100644
  			const newDocument = new DOMParser().parseFromString(text, 'text/html');
  
  			newDocument.querySelectorAll('a').forEach(a => {
-@@ -265,6 +265,12 @@
+@@ -379,7 +379,7 @@
- 				}
- 			});
  
-+			// REVIEW: Why is it required for scripts to be loaded at the end?
+ 				newFrame.contentWindow.addEventListener('keydown', handleInnerKeydown);
-+			// Without this the document in the iframe appears to simply truncate.
+ 
-+			newDocument.querySelectorAll('script').forEach(script => {
+-				newFrame.contentWindow.addEventListener('DOMContentLoaded', e => {
-+				newDocument.body.appendChild(script);
++				newFrame.contentWindow.addEventListener('load', e => {
-+			});
+ 					if (host.fakeLoad) {
-+
+ 						newFrame.contentDocument.open();
- 			// apply default script
+ 						newFrame.contentDocument.write(newDocument);
- 			if (options.allowScripts) {
- 				const defaultScript = newDocument.createElement('script');
 diff --git a/src/vs/workbench/contrib/welcome/walkThrough/browser/editor/editorWalkThrough.ts b/src/vs/workbench/contrib/welcome/walkThrough/browser/editor/editorWalkThrough.ts
 index 7a95ffda9e..fdb14da4ee 100644
 --- a/src/vs/workbench/contrib/welcome/walkThrough/browser/editor/editorWalkThrough.ts

src/util.ts

@@ -66,7 +66,7 @@ export const getMediaMime = (filePath?: string): string => {
 	return filePath && (vsGetMediaMime(filePath) || (<{[index: string]: string}>{
 		".css": "text/css",
 		".html": "text/html",
-		".js": "text/javascript",
+		".js": "application/javascript",
 		".json": "application/json",
 	})[extname(filePath)]) || "text/plain";
 };