DevTools: support uiLocationToRawLocations for CSS

third_party/WebKit/LayoutTests/inspector/sources/formatter-css-expected.txt

 Tests how SourceFormatter handles CSS sources
 
 Formatted:
 @media screen {
     html {
         color: green;
         foo-property: bar-value
     }
 }
 }
 
 body {
     background-color: black;
 }
 
 Location mapping with formatted source:
 Mapped locations:
-0:15 -> 0:14
-0:22 -> 1:9
-0:65 -> 8:5
+0:15 -> 0:14 -> 0:15
+0:22 -> 1:9 -> 0:22
+0:65 -> 8:5 -> 0:65
 Live locations (updated: 3):
 0:14
 1:9
 8:5
 Location mapping without formatted source:
 Mapped locations:
-0:15 -> 0:15
-0:22 -> 0:22
-0:65 -> 0:65
+0:15 -> 0:15 -> 0:15
+0:22 -> 0:22 -> 0:22
+0:65 -> 0:65 -> 0:65
 Live locations (updated: 6):
 0:15
 0:22
 0:65