fix(compiler): always use ng:// prefix for sourcemap urls (#15218)

Fixes:
- In G3, filePaths don’t start with a `/` and therefore became relative.
- Always using the `ng://` prefix groups angular resources in the same
  way for AOT and JIT.

packages/compiler/src/compile_metadata.ts

@@ -758,42 +758,43 @@ export function flatten<T>(list: Array<T|T[]>): T[] {
   }, []);
 }
 
-/**
- * Note: Using `location.origin` as prefix helps displaying them as a hierarchy in chrome.
- * It also helps long-stack-trace zone when rewriting stack traces to not break
- * source maps (as now all scripts have the same origin).
- */
-function ngJitFolder() {
-  return 'ng://';
+export function sourceUrl(url: string) {
+  // Note: We need 3 "/" so that ng shows up as a separate domain
+  // in the chrome dev tools.
+  return url.replace(/(\w+:\/\/[\w:-]+)?(\/+)?/, 'ng:///');
 }
 
 export function templateSourceUrl(
     ngModuleType: CompileIdentifierMetadata, compMeta: {type: CompileIdentifierMetadata},
     templateMeta: {isInline: boolean, templateUrl: string}) {
+  let url: string;
   if (templateMeta.isInline) {
     if (compMeta.type.reference instanceof StaticSymbol) {
       // Note: a .ts file might contain multiple components with inline templates,
       // so we need to give them unique urls, as these will be used for sourcemaps.
-      return `${compMeta.type.reference.filePath}#${compMeta.type.reference.name}.html`;
+      url = `${compMeta.type.reference.filePath}.${compMeta.type.reference.name}.html`;
     } else {
-      return `${ngJitFolder()}/${identifierName(ngModuleType)}/${identifierName(compMeta.type)}.html`;
+      url = `${identifierName(ngModuleType)}/${identifierName(compMeta.type)}.html`;
     }
   } else {
-    return templateMeta.templateUrl;
+    url = templateMeta.templateUrl;
   }
+  // always prepend ng:// to make angular resources easy to find and not clobber
+  // user resources.
+  return sourceUrl(url);
 }
 
 export function sharedStylesheetJitUrl(meta: CompileStylesheetMetadata, id: number) {
   const pathParts = meta.moduleUrl.split(/\/\\/g);
   const baseName = pathParts[pathParts.length - 1];
-  return `${ngJitFolder()}/css/${id}${baseName}.ngstyle.js`;
+  return sourceUrl(`css/${id}${baseName}.ngstyle.js`);
 }
 
 export function ngModuleJitUrl(moduleMeta: CompileNgModuleMetadata): string {
-  return `${ngJitFolder()}/${identifierName(moduleMeta.type)}/module.ngfactory.js`;
+  return sourceUrl(`${identifierName(moduleMeta.type)}/module.ngfactory.js`);
 }
 
 export function templateJitUrl(
     ngModuleType: CompileIdentifierMetadata, compMeta: CompileDirectiveMetadata): string {
-  return `${ngJitFolder()}/${identifierName(ngModuleType)}/${identifierName(compMeta.type)}.ngfactory.js`;
+  return sourceUrl(`${identifierName(ngModuleType)}/${identifierName(compMeta.type)}.ngfactory.js`);
 }