telemetry: Add GetRendererProcessFromTab to timeline model.

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

Index: tools/telemetry/telemetry/core/backends/chrome/chrome_trace_result.py
diff --git a/tools/telemetry/telemetry/core/backends/chrome/chrome_trace_result.py b/tools/telemetry/telemetry/core/backends/chrome/chrome_trace_result.py
new file mode 100644
index 0000000000000000000000000000000000000000..00c21048670d38d0e18d7975772dd0f5d8d2ab2a
--- /dev/null
+++ b/tools/telemetry/telemetry/core/backends/chrome/chrome_trace_result.py
@@ -0,0 +1,30 @@
+# Copyright 2013 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 ChromeTraceResult(object):
+  def __init__(self, tracing_data, tab_to_marker_mapping = None):
+    self._tracing_data = tracing_data
+    if tab_to_marker_mapping == None:
+      self._tab_to_marker_mapping = {}
+    else:
+      self._tab_to_marker_mapping = tab_to_marker_mapping
+
+  def Serialize(self, f):
+    """Serializes the trace result to a file-like object"""
+    raise NotImplementedError()
+
+  def AsTimelineModel(self):
+    """Parses the trace result into a timeline model for in-memory
+    manipulation."""
+    timeline = self._CreateTimelineModel()
+    for key, value in self._tab_to_marker_mapping.iteritems():
+      timeline_markers = timeline.FindTimelineMarkers(value)
+      assert(len(timeline_markers) == 1)
+      renderer_process = timeline_markers[0].start_thread.parent
+      timeline.AddCoreObjectToContainerMapping(key, renderer_process)
+    return timeline
+
+  def _CreateTimelineModel(self):
+    raise NotImplementedError()