Move browser and url to WebContents from Tab.

tools/telemetry/telemetry/core/tab.py

Index: tools/telemetry/telemetry/core/tab.py
===================================================================
--- tools/telemetry/telemetry/core/tab.py	(revision 192364)
+++ tools/telemetry/telemetry/core/tab.py	(working copy)
@@ -23,15 +23,6 @@
     super(Tab, self).__del__()
 
   @property
-  def browser(self):
-    """The browser in which this tab resides."""
-    return self._inspector_backend.browser
-
-  @property
-  def url(self):
-    return self._inspector_backend.url
-
-  @property
   def dom_stats(self):
     """A dictionary populated with measured DOM statistics.