Auto merge of #12137 - ConnorGBrewster:resources_case_sensitive, r=aneeshusa

Check for Resources on case sensitive filesystem

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http://logs.glob.uno/?c=mozilla%23servo&s=1+Jul+2016&e=1+Jul+2016#c471192

Another option is to make the Resources folder on the mac .app bundle be lower case; however, it is standard to have `Resources` in a .app bundle.

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components/util/resource_files.rs

@@ -46,6 +46,12 @@ pub fn resources_dir_path() -> PathBuf {
             break;
         }
         path.pop();
+        // Check for Resources on mac when using a case sensitive filesystem.
+        path.push("Resources");
+        if path.is_dir() {
+            break;
+        }
+        path.pop();
     }
     *dir = Some(path.to_str().unwrap().to_owned());
     path