Add profiling_controller that manages profilers.

tools/telemetry/telemetry/core/platform/profiling_controller.py

Index: tools/telemetry/telemetry/core/platform/profiling_controller.py
diff --git a/tools/telemetry/telemetry/core/platform/profiling_controller.py b/tools/telemetry/telemetry/core/platform/profiling_controller.py
new file mode 100644
index 0000000000000000000000000000000000000000..3387c06aeb4d863aa22b65af5ac0e9bc3b4af673
--- /dev/null
+++ b/tools/telemetry/telemetry/core/platform/profiling_controller.py
@@ -0,0 +1,18 @@
+# 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.
+
+
+class ProfilingController(object):
+  def __init__(self, profiling_controller_backend):
+    self._profiling_controller_backend = profiling_controller_backend
+
+  def StartProfiling(self, profiler_name, base_output_file):

[tonyg, 2014/09/04 17:10:19]

I'd prefer the more terse names Start() and Stop() and IsActive() since they're
on a class already named ProfilingController.

[nednguyen, 2014/09/05 17:08:43]

Done. I also remove is_profiler_active since it's no longer used.

+    self._profiling_controller_backend.StartProfiling(
+        profiler_name, base_output_file)
+
+  def StopProfiling(self):
+    return self._profiling_controller_backend.StopProfiling()
+
+  def is_profiler_active(self, profiler_name):
+    return self._profiling_controller_backend.is_profiler_active(profiler_name)