Remove deprecated methods related to tracing in browser.py.

tools/telemetry/telemetry/web_perf/timeline_based_measurement.py

Index: tools/telemetry/telemetry/web_perf/timeline_based_measurement.py
diff --git a/tools/telemetry/telemetry/web_perf/timeline_based_measurement.py b/tools/telemetry/telemetry/web_perf/timeline_based_measurement.py
index 709c8a3dd4ced014a45a73f54b63718ad9d26b74..c399fcacd41564e25e0f621b91dc0a05f2f56b13 100644
--- a/tools/telemetry/telemetry/web_perf/timeline_based_measurement.py
+++ b/tools/telemetry/telemetry/web_perf/timeline_based_measurement.py
@@ -8,6 +8,7 @@ from collections import defaultdict
 
 from telemetry.core import util
 from telemetry.core.platform import tracing_category_filter
+from telemetry.core.platform import tracing_options
 from telemetry.page import page_test
 from telemetry.timeline import model as model_module
 from telemetry.value import string as string_value_module
@@ -152,7 +153,8 @@ class TimelineBasedMeasurement(page_test.PageTest):
               'is not set, the trace will not be saved.'))
 
   def WillNavigateToPage(self, page, tab):
-    if not tab.browser.supports_tracing:
+    if not tab.browser.platform.tracing_controller.IsChromeTracingSupported(
+        tab.browser):
       raise Exception('Not supported')
 
     assert self.options.overhead_level in ALL_OVERHEAD_LEVELS
@@ -170,12 +172,13 @@ class TimelineBasedMeasurement(page_test.PageTest):
 
     for delay in page.GetSyntheticDelayCategories():
       category_filter.AddSyntheticDelay(delay)
-
-    tab.browser.StartTracing(category_filter)
+    options = tracing_options.TracingOptions()
+    options.enable_chrome_trace = True
+    tab.browser.platform.tracing_controller.Start(options, category_filter)
 
   def ValidateAndMeasurePage(self, page, tab, results):
     """ Collect all possible metrics and added them to results. """
-    trace_result = tab.browser.StopTracing()
+    trace_result = tab.browser.platform.tracing_controller.Stop()
     trace_dir = self.options.trace_dir
     if trace_dir:
       trace_file_path = util.GetSequentialFileName(
@@ -195,5 +198,5 @@ class TimelineBasedMeasurement(page_test.PageTest):
     meta_metrics.AddResults(results)
 
   def CleanUpAfterPage(self, page, tab):
-    if tab.browser.is_tracing_running:
-      tab.browser.StopTracing()
+    if tab.browser.platform.tracing_controller.is_tracing_running:
+      tab.browser.platform.tracing_controller.Stop()