Remove deprecated methods related to tracing in browser.py.

tools/telemetry/telemetry/core/backends/chrome/tracing_backend_unittest.py

Index: tools/telemetry/telemetry/core/backends/chrome/tracing_backend_unittest.py
diff --git a/tools/telemetry/telemetry/core/backends/chrome/tracing_backend_unittest.py b/tools/telemetry/telemetry/core/backends/chrome/tracing_backend_unittest.py
index 0f5027b188b83f66170b17f8ba119dedcdd27e5c..fffc978ca7458a979661179ac53e8c4758c21f8f 100644
--- a/tools/telemetry/telemetry/core/backends/chrome/tracing_backend_unittest.py
+++ b/tools/telemetry/telemetry/core/backends/chrome/tracing_backend_unittest.py
@@ -8,6 +8,8 @@ import logging
 import unittest
 
 from telemetry.core import util
+from telemetry.core.platform import tracing_category_filter
+from telemetry.core.platform import tracing_options
 from telemetry.timeline import model
 from telemetry.timeline import tracing_timeline_data
 from telemetry.unittest import tab_test_case
@@ -24,15 +26,18 @@ class TracingBackendTest(tab_test_case.TabTestCase):
     util.WaitFor(_IsDone, 5)
 
   def testGotTrace(self):
-    if not self._browser.supports_tracing:
+    tracing_controller = self._browser.platform.tracing_controller
+    if not tracing_controller.IsChromeTracingSupported(self._browser):
       logging.warning('Browser does not support tracing, skipping test.')
       return
     self._StartServer()
-    self._browser.StartTracing()
-    self._browser.StopTracing()
-
-    # TODO(tengs): check model for correctness after trace_event_importer
-    # is implemented (crbug.com/173327).
+    options = tracing_options.TracingOptions()
+    options.enable_chrome_trace = True
+    tracing_controller.Start(
+      options, tracing_category_filter.TracingCategoryFilter())
+    trace_data = tracing_controller.Stop()
+    # Test that trace data is parsable
+    model.TimelineModel(trace_data)
 
 
 class ChromeTraceResultTest(unittest.TestCase):