[Telemetry] Platform-level tracing

tools/telemetry/telemetry/core/tracing_controller_unittest.py

Index: tools/telemetry/telemetry/core/tracing_controller_unittest.py
diff --git a/tools/telemetry/telemetry/core/tracing_controller_unittest.py b/tools/telemetry/telemetry/core/tracing_controller_unittest.py
index 2b58d7d41a4428b1a19df7fd114d2ce22b58239c..adb5dc8ba52a5bda31dd88430feeb89c19313823 100644
--- a/tools/telemetry/telemetry/core/tracing_controller_unittest.py
+++ b/tools/telemetry/telemetry/core/tracing_controller_unittest.py
@@ -2,6 +2,9 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+from telemetry import decorators
+from telemetry.core import platform as platform_module
+from telemetry.testing import browser_test_case
 from telemetry.testing import tab_test_case
 from telemetry.timeline import model as model_module
 from telemetry.timeline import tracing_category_filter
@@ -84,3 +87,46 @@ class TracingControllerTest(tab_test_case.TabTestCase):
     self.assertFalse(tracing_controller.is_tracing_running)
     # Calling stop again will raise exception
     self.assertRaises(Exception, tracing_controller.Stop)
+
+  def _StartupTracing(self, platform):
+    # Stop browser
+    browser_test_case.teardown_browser()
+
+    # Start tracing
+    self.assertFalse(platform.tracing_controller.is_tracing_running)
+    trace_options = tracing_options.TracingOptions()
+    trace_options.enable_chrome_trace = True
+    category_filter = tracing_category_filter.TracingCategoryFilter()
+    platform.tracing_controller.Start(trace_options, category_filter)
+    self.assertTrue(platform.tracing_controller.is_tracing_running)
+
+    try:
+      # Start browser
+      self.setUpClass()
+      self._browser.tabs[0].Navigate('about:blank')
+      self._browser.tabs[0].WaitForDocumentReadyStateToBeInteractiveOrBetter()
+      self.assertEquals(platform, self._browser.platform)
+      # Calling start tracing again will return False
+      self.assertFalse(self._browser.platform.tracing_controller.Start(
+          trace_options, category_filter))
+
+      trace_data = self._browser.platform.tracing_controller.Stop()
+      # Test that trace data is parsable
+      model_module.TimelineModel(trace_data)
+      self.assertFalse(
+          self._browser.platform.tracing_controller.is_tracing_running)
+      # Calling stop tracing again will raise exception
+      self.assertRaises(Exception,
+                        self._browser.platform.tracing_controller.Stop)
+    finally:
+      if self._browser:
+        self._browser.Close()
+        self._browser = None
+
+  @decorators.Enabled('android')
+  def testStartupTracingOnAndroid(self):
+    self._StartupTracing(self._browser.platform)
+
+  @decorators.Enabled('linux', 'mac', 'win')
+  def testStartupTracingOnDesktop(self):
+    self._StartupTracing(platform_module.GetHostPlatform())