[Telemetry] Add tracing_agent API.

tools/telemetry/telemetry/core/platform/tracing_agent/chrome_tracing_agent_unittest.py

Index: tools/telemetry/telemetry/core/platform/tracing_agent/chrome_tracing_agent_unittest.py
diff --git a/tools/telemetry/telemetry/core/platform/tracing_agent/chrome_tracing_agent_unittest.py b/tools/telemetry/telemetry/core/platform/tracing_agent/chrome_tracing_agent_unittest.py
new file mode 100644
index 0000000000000000000000000000000000000000..e922c51c237ee73cc650998ed94755115754dc9c
--- /dev/null
+++ b/tools/telemetry/telemetry/core/platform/tracing_agent/chrome_tracing_agent_unittest.py
@@ -0,0 +1,144 @@
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import unittest
+
+from telemetry.core.platform.tracing_agent import chrome_tracing_agent
+
+
+class FakePlatformBackend(object):
+  pass
+
+
+class FakeDevtoolsClient(object):
+  def __init__(self, remote_port):
+    self.is_alive = True
+    self.tracing_started = False
+    self.remote_port = remote_port
+
+  def IsAlive(self):
+    return self.is_alive
+
+  def StartChromeTracing(self, _trace_options, _filter_string, _timeout=10):
+    self.tracing_started = True
+
+  def StopChromeTracing(self, _trace_data_builder):
+    self.tracing_started = False
+
+  def IsChromeTracingSupported(self):
+    return True
+
+
+class FakeTraceOptions(object):
+  def __init__(self):
+    self.enable_chrome_trace = True
+
+
+class FakeCategoryFilter(object):
+  def __init__(self):
+    self.filter_string = 'foo'
+
+
+class ChromeTracingAgentUnittest(unittest.TestCase):
+  def setUp(self):
+    self.platform1 = FakePlatformBackend()
+    self.platform2 = FakePlatformBackend()
+    self.platform3 = FakePlatformBackend()
+
+  def StartTracing(self, platform_backend, enable_chrome_trace=True):
+    assert chrome_tracing_agent.ChromeTracingAgent.IsSupported(platform_backend)
+    agent = chrome_tracing_agent.ChromeTracingAgent(platform_backend)
+    trace_options = FakeTraceOptions()
+    trace_options.enable_chrome_trace = enable_chrome_trace
+    agent.Start(trace_options, FakeCategoryFilter(), 10)
+    return agent
+
+  def StopTracing(self, tracing_agent):
+    tracing_agent.Stop(None)
+
+  def testRegisterDevtoolsClient(self):
+    chrome_tracing_agent.ChromeTracingAgent.RegisterDevToolsClient(
+        FakeDevtoolsClient(1), self.platform1)
+    chrome_tracing_agent.ChromeTracingAgent.RegisterDevToolsClient(
+        FakeDevtoolsClient(2), self.platform1)
+    chrome_tracing_agent.ChromeTracingAgent.RegisterDevToolsClient(
+        FakeDevtoolsClient(3), self.platform1)
+
+    tracing_agent_of_platform1 = self.StartTracing(self.platform1)
+
+    with self.assertRaises(chrome_tracing_agent.ChromeTracingStartedError):
+      chrome_tracing_agent.ChromeTracingAgent.RegisterDevToolsClient(
+          FakeDevtoolsClient(4), self.platform1)
+    chrome_tracing_agent.ChromeTracingAgent.RegisterDevToolsClient(
+        FakeDevtoolsClient(5), self.platform2)
+
+    self.StopTracing(tracing_agent_of_platform1)
+    chrome_tracing_agent.ChromeTracingAgent.RegisterDevToolsClient(
+        FakeDevtoolsClient(6), self.platform1)
+
+  def testIsSupport(self):
+    self.assertFalse(
+        chrome_tracing_agent.ChromeTracingAgent.IsSupported(self.platform1))
+    self.assertFalse(
+        chrome_tracing_agent.ChromeTracingAgent.IsSupported(self.platform2))
+    self.assertFalse(
+        chrome_tracing_agent.ChromeTracingAgent.IsSupported(self.platform3))
+
+    devtool1 = FakeDevtoolsClient(1)
+    devtool2 = FakeDevtoolsClient(2)
+    chrome_tracing_agent.ChromeTracingAgent.RegisterDevToolsClient(
+        devtool1, self.platform1)
+    chrome_tracing_agent.ChromeTracingAgent.RegisterDevToolsClient(
+        devtool2, self.platform2)
+    devtool2.is_alive = False
+
+    # Chrome tracing is only supported on platform 1 since only platform 1 has
+    # an alive devtool.
+    self.assertTrue(
+        chrome_tracing_agent.ChromeTracingAgent.IsSupported(self.platform1))
+    self.assertFalse(
+        chrome_tracing_agent.ChromeTracingAgent.IsSupported(self.platform2))
+    self.assertFalse(
+        chrome_tracing_agent.ChromeTracingAgent.IsSupported(self.platform3))
+
+  def testStartAndStopTracing(self):
+    devtool1 = FakeDevtoolsClient(1)
+    devtool2 = FakeDevtoolsClient(2)
+    devtool3 = FakeDevtoolsClient(3)
+    devtool4 = FakeDevtoolsClient(2)
+    # Register devtools 1, 2, 3 on platform1 and devtool 4 on platform 2
+    chrome_tracing_agent.ChromeTracingAgent.RegisterDevToolsClient(
+        devtool1, self.platform1)
+    chrome_tracing_agent.ChromeTracingAgent.RegisterDevToolsClient(
+        devtool2, self.platform1)
+    chrome_tracing_agent.ChromeTracingAgent.RegisterDevToolsClient(
+        devtool3, self.platform1)
+    chrome_tracing_agent.ChromeTracingAgent.RegisterDevToolsClient(
+        devtool4, self.platform2)
+    devtool2.is_alive = False
+
+    tracing_agent1 = self.StartTracing(self.platform1)
+    with self.assertRaises(chrome_tracing_agent.ChromeTracingStartedError):
+      self.StartTracing(self.platform1)
+
+    self.assertTrue(devtool1.tracing_started)
+    self.assertFalse(devtool2.tracing_started)
+    self.assertTrue(devtool3.tracing_started)
+    # Devtool 4 shouldn't have tracing started although it has the same remote
+    # port as devtool 2
+    self.assertFalse(devtool4.tracing_started)
+
+    self.StopTracing(tracing_agent1)
+    self.assertFalse(devtool1.tracing_started)
+    self.assertFalse(devtool2.tracing_started)
+    self.assertFalse(devtool3.tracing_started)
+    self.assertFalse(devtool4.tracing_started)
+    # Test that it should be ok to start & stop tracing on platform1 again.
+    tracing_agent1 = self.StartTracing(self.platform1)
+    self.StopTracing(tracing_agent1)
+
+    tracing_agent2 = self.StartTracing(self.platform2)
+    self.assertTrue(devtool4.tracing_started)
+    self.StopTracing(tracing_agent2)
+    self.assertFalse(devtool4.tracing_started)