[telemetry] Support absolute paths by changing file:/// to file://. More robust file path handling.

tools/telemetry/telemetry/core/browser.py

Index: tools/telemetry/telemetry/core/browser.py
diff --git a/tools/telemetry/telemetry/core/browser.py b/tools/telemetry/telemetry/core/browser.py
index 93388974eaf242a75b8a3a9e0aa1542cd5a93cb5..38f9aead7ff5467bc4cc2cbc50ee2018e7b17bfb 100644
--- a/tools/telemetry/telemetry/core/browser.py
+++ b/tools/telemetry/telemetry/core/browser.py
@@ -294,14 +294,14 @@ class Browser(object):
 
   def SetHTTPServerDirectories(self, paths):
     """Returns True if the HTTP server was started, False otherwise."""
-    if not isinstance(paths, list):
-      paths = [paths]
-    paths = [os.path.abspath(p) for p in paths]
-
-    if paths and self._http_server and self._http_server.paths == paths:
-      return False
+    if isinstance(paths, basestring):
+      paths = set([paths])
+    paths = set(os.path.realpath(p) for p in paths)
 
     if self._http_server:
+      if paths and self._http_server.paths == paths:
+        return False
+
       self._http_server.Close()
       self._http_server = None