DevTools: [Persistence] implement automapping

third_party/WebKit/LayoutTests/http/tests/inspector/persistence/automapping-git-folders-expected.txt

+Verify that automapping is able to map ambiguous resources based on the selected project folder.
+
+Binding created: {
+       network: http://example.com/logo.png
+    fileSystem: file:///var/www/code/proj2/logo.png
+    exactMatch: true
+}
+Binding created: {
+       network: http://example.com/reset.css
+    fileSystem: file:///var/www/code/proj2/reset.css
+    exactMatch: true
+}
+Binding created: {
+       network: http://example.com/jquery.js
+    fileSystem: file:///var/www/code/proj2/jquery.js
+    exactMatch: true
+}
+Mapping has stabilized.
+